Sonic screwdriver

The Sonic Screwdriver was a versatile tool and defensive weapon used by the Doctor.

Technology and functions
The origin of the sonic screwdriver was unknown. It may have been the product of Gallifreyan technology since Romana understood it enough to construct her own version of it. It may have even been a design of the First Doctor himself during his adolescence, rather than wooing a woman who wanted to kiss him. (DW: A Christmas Carol). Other alien races were known to possess similar devices, such as the sonic pen used by Miss Foster (DW: Partners in Crime) and the sonic blaster obtained by Captian Harkness. Sonic blasters were known to be made in the Villengard factory. (The Empty Child) The name of the device itself suggests that it functioned using sound waves, although the actual workings of the device were never fully explained.

A crystal similar to Metebelis Crystal sought after by the Eight Legs of Metebelis III was used in the Mark VI sonic screwdriver. (IDW: The Forgotten) There were also electrical components. (DWAM: The Halls of Sacrifice)

The screwdriver had a multitude of settings, along with different versions of settings, as the Doctor told Rose to use "setting 15B" to help him triangulate the source of the ghosts (DW: Army of Ghosts) and used 34-H to sink a ship (DWBIT: Second Wave). It is also said to have a setting 85. (DW: The Lazarus Experiment). The Doctor told Rose to use setting 2428D to re-attach barbed wire. (DW: The Doctor Dances)

The different versions of the Doctor's sonic screwdrivers exhibited different capabilities and uses, such as the interception of signals ranging from transmat beams to conscious thought; medical diagnostics and repair of organic parts; cutting, but also re-attaching together materials such as barbed wire; operating Earth machinery such as computers and even cash machines (at regular and high eject speeds); creating a spark to light a candle; and, on the rare occasion, driving screws without touching them. Although it was primarily a tool, it could also be used as a defensive weapon, such as when the Tenth Doctor put it in a sound board to destroy the Robot Santas. (DW: The Runaway Bride) Although the Eighth Doctor once claimed that the device could destroy a Dalek's brain if held directly against the casing when activated (EDA: War of the Daleks), according to the Tenth Doctor, the device could not be used to wound, maim, or kill living things. (DW: Doomsday) It could still be used to destroy non-living objects or mechanisms or place living creatures in circumstances where they might die, if the situation required.

From time to time, the sonic screwdriver needed to be recharged. (NSA: The Monsters Inside, DWAM: Bizarre Zero)

Sonic screwdrivers and similar technology could not unlock a deadlock seal (DW: School Reunion); one of few exceptions was Miss Foster's sonic pen, which was able to open the deadlock seals on and within the Adipose Industries building when the Doctor's sonic screwdriver could not. (DW: Partners in Crime) Some or all versions may be ineffective against wood, or in the presence of some models of hairdryers. (DW: Silence in the Library/Forest of the Dead, The Hungry Earth, PDA: Catastrophea)

Mark I
A small, simple device similar to a penlight, first used by the Doctor in his first (MA: Venusian Lullaby) and second incarnations. (DW: Fury from the Deep)

Known uses

 * Cracking the code for an aerodynamic shuttle. (MA: ''Venusian Lullaby).
 * Opening up hatches, panels and control panels. (DW: Fury from the Deep, The War Games)
 * For cutting through a section of a wall. (DW: The Dominators)
 * As a conventional screwdriver (without touching the screws). (DW: The War Games)

Mark II
A larger and more elaborately detailed version, the Doctor began using this model in his third incarnation. In addition to a redesign on the tip which remained the norm for the next two versions, it had a silver handle, and black and yellow stripes. It had a removable head which the Doctor would change with other heads, each doing a different function. (DW: The Sea Devils)

Known uses

 * To remotely open his workshop. (DW: Inferno)
 * Booby trap detector in the Master's TARDIS. (DW: Colony in Space)
 * Remote detection and detonation of land mines. (DW: The Sea Devils)
 * To open an electronic door. (DW: The Mutants)
 * Undoing wrist clamps. (DW: The Mutants)
 * Creation of a spark of fire and igniting swamp gas. (DW: Carnival of Monsters)
 * Open electronic locks. (DW: Carnival of Monsters)
 * As conventional screwdriver, on large, flathead screw. (DW: The Monster of Peladon)
 * Overloading the brains of Space Greyhounds. (IDW: The Forgotten)
 * To distract giant maggots. (DW: The Green Death)

Mark III
The Fourth Doctor remade his sonic screwdriver into a silver version that lacked the interchangeable heads. It was capable of extending its tip.

Known uses

 * Remotely detonating mines. (DW: Robot)
 * Cutting locks. (DW: Robot)
 * Fixing a circle of transmat refractors. (DW: The Sontaran Experiment)
 * Breaching a force field. (DW: The Sontaran Experiment)
 * Shutting down Styre's Robot. (DW: The Sontaran Experiment)
 * Sabotaging a two-way radio. (DW: Genesis of the Daleks)
 * Shattering the Clynex. (DWM: The Naked Flame)
 * Creating a temporary hole in Gallifrey's force field above the Citadel. (DW: The Invasion of Time)
 * Using the correct sonic frequency to return The Doctor and Ernestina Stott to normal size. (BBCR: Hornets' Nest - The Dead Shoes)
 * Opening doors on Ribos. (DW: The Ribos Operation)
 * Unlocking multi-levered interlocks to the Ribos crown jewels casket (DW: The Ribos Operation)
 * Opening the door to the real Queen Xanxia's camber. (DW: The Pirate Planet)
 * Blowing up a Dalek bomb. (DW: Destiny of the Daleks)
 * Disarming fusion bombs by reversing the polarity of the neutron-flow. (MA: Cold Fusion)

Mark IV
Towards the end of his Seventh Incarnation The Doctor used a model quite similar to his Mark III except that instead of the ring around the tip being red, the tip it self was red. This is used during the Eighth Doctor's life and had a torch built in the handle.

Known Uses

 * To lock the casket containing the Master's remains. (DW: Doctor Who)
 * Turn Cybermen against each other. (DWM: The Flood)
 * Destroy a Dalek's brain (When placed directly against the Dalek's head) (EDA: War of the Daleks)
 * Repel ghosts (EDA: Vanderdeken's Children)
 * Open a door in a force field large enough for the Doctor and his companions to travel through. (EDA: EarthWorld).

Mark V
In his ninth incarnation the Doctor had a new model with a glowing blue diode at one end. The tenth incarnation of the Doctor also carried this model, until it was burnt out after modifying an x-ray scanner to increase the radiation output. (DW: Smith and Jones)

Known uses

 * To destroy the controls of an elevator. (DW: Rose)
 * Detecting and stopping telepathic signals. (DW: Rose)
 * Interfacing with a computer. (DW: The End of the World)
 * To control an elevator. (DW: Aliens of London)
 * Atmospheric excitation to cause rain. (DWM: Death to the Doctor!)
 * Obtaining money from a cash machine. (DW: The Long Game)
 * Battery charging. (DW: Father's Day)
 * As a medical scanner and diagnostic tool. (DW: The Empty Child)
 * Completely corroding thin metal (e.g. barbed wire) so that it crumbles into rust. (DW: The Doctor Dances)
 * Re-connecting barbed wire. (DW: The Doctor Dances)
 * Unlocking handcuffs. (DW: The Doctor Dances)
 * Setting up a resonation pattern in concrete. (DW: The Doctor Dances)
 * Reversing teleport devices. (DW: Boom Town)
 * To destroy a television camera. (DW: Bad Wolf)
 * Dematerialising the TARDIS and initialising TARDIS processes from outside the craft. (DW: The Parting of the Ways)
 * Blowing up a remote control Christmas tree. (DW: The Christmas Invasion)
 * To transfer its powers to a remote control. (DW: Attack of the Graske)
 * Igniting swamp gas. (DWAM: The Hunt of Doom)
 * Stop the emergence of Mirrorlings from mirrors. (DWAM: Mirror Image)
 * Dislodging and reinserting teeth. (DWM: The Lodger)
 * To create small flames. (DW: The Girl in the Fireplace)
 * To cut rope. (DW: The Age of Steel)
 * Locking / unlocking a hatch in Cybus Industries (DW: The Age of Steel)
 * To threaten the Wire. (DW: The Idiot's Lantern)
 * Illuminate Rose. (DWAM: Warfreekz!)
 * Reverse an anti-gravity umbrella. (DWAM: Smart Bombs)
 * To partially reverse the Abzorbaloff's absorption of Ursula Blake. (DW: Love & Monsters)
 * To de-activate a living graphite scribble. (DW: Fear Her)
 * Partially cracking glass so it can be smashed with the push of a finger. (DW: Army of Ghosts)
 * Detonation of an explosive device. (DW: Doomsday)
 * Get money from cash machine, at both regular and extra-high rates of ejection. (DW: The Runaway Bride)
 * To unlock a taxi door and window. (DW: The Runaway Bride)
 * Scan a life form for information, specifically Donna Noble. (DW: The Runaway Bride)
 * To detonate the head of a roboform (DW: The Runaway Bride)
 * Search a phone for an app or a feature. (DW: The Runaway Bride)
 * Hacking into the H.C. Clements website. (DW: The Runaway Bride)
 * Bypass the key needed to access the secret basement in H.C. Clements. (DW: The Runaway Bride)
 * Able to summon the Tardis using Huon particles. (DW: The Runaway Bride)
 * To cut a spider web. (DW: The Runaway Bride)
 * To destroy the Robot Santas with sound (used in conjunction with a professional sound system). (DW: The Runaway Bride)
 * Detect heated water. (DWAM: The Halls of Sacrifice)
 * Overload Cybermen. (DWBIT: The Power of the Cybermen)
 * Crashing an aircar. (DWBIT: Time of the Cybermen)
 * Confusing the antibodies of a living planet. (DWBIT: Lonely Planet)
 * To increase the radiation output of a device such as an x-ray scanner; this action burned out the screwdriver. (DW: Smith and Jones)

Mark VI
The tenth incarnation used another screwdriver after the X-ray incident. This model was damaged during the Doctor's tenth regeneration and the TARDIS' subsequent crash, as well as by Prisoner Zero and was ultimately destroyed when the Doctor used it to overload technology to alert the Atraxi. (DW: The Eleventh Hour)

Known uses



 * Opening air-tight seals. (DW: Gridlock)
 * Trying to strip off pieces of Dalekanium. (DW: Evolution of the Daleks)
 * Lighting a bunsen burner from a distance. (DW: Evolution of the Daleks)
 * Bypassing and turning off security systems. (DW: The Lazarus Experiment)
 * In conjunction with a pipe organ, it produced hypersonic sound waves which led to the death of the Lazarus creature. (DW: The Lazarus Experiment)
 * Scanning for the transformed Lazarus creature after it escaped to Southwark Cathedral. (DW: The Lazarus Experiment)
 * Disabling robotic flies. (DWBIT: Exhausting Evil)
 * Disabling security orbs. (DWBIT: Wrath of the Warrior)
 * Modifying hearing aids. (DWBIT: The Screaming Prison)
 * Reversing teleport feeds. (DWBIT: Warriors' Revenge)
 * Sinking a ship. (DWBIT: Second Wave)
 * Resonate a floor to destroy it, via crystal gems. (DWBIT: Operation Lock-up)
 * Melting chocolate by increasing the resonance frequency of a torch. (DWBIT: Crimes and Punishment)
 * Completing the life's work of Professor Yana, allowing the Human race to travel to Utopia (DW Utopia)
 * Locking the TARDIS navigational systems to only allow travel between its current position and its previous position. (DW: Utopia)
 * Fixing a decades-broken Vortex Manipulator. (DW: Utopia)
 * To destroy a security camera. (DW: The Sound of Drums)
 * As a soldering iron to make perception filters using TARDIS keys. (DW: The Sound of Drums)
 * Uncorking a wine bottle. (DW: Voyage of the Damned)
 * Loop temporal energy of a fraxis pod back into a the zygma drive. (DWBIT: Blooms of Doom!)
 * Shatter robot assassins. (DWBIT: A Suitable Showdown)
 * Controlling a cable cart. (DW: Partners in Crime)
 * Breaking into a silo on the Ood-Sphere. (DW: Planet of the Ood)
 * Create a stasis beam. (DWBIT: School of the Dead)
 * Disabling a Sontaran teleport. (DW: The Sontaran Stratagem)
 * Scanning shadows for the presence of Vashta Nerada. (DW: Silence in the Library/Forest of the Dead)
 * Showing a hologram of Donna Noble. (DW: Forest of the Dead)
 * Tinting a Helmet Visor (DW: Forest of the Dead)
 * Disabling the Crusader 50's entertainment system. (DW: Midnight)
 * Checking Crusader 50's control console for faults. (DW: Midnight)
 * Teleporting a Graske to the other side of the universe. (DW: Music of the Spheres)
 * Opening the casing of a cleaning robot. (DWBIT: Carnage Zoo)
 * Teleporting onto a Nim spacecraft. (DWBIT: The Day the Earth Was Sold, The King of Earth)
 * As a Sonic Toothbrush. (DWAM: The Continuity Cap)
 * Tracing distress signals. (DWAM: The Ghost Factory)
 * Modifying a gravity converter. (DWAM: Skydive)
 * Disabling a Cyrronak Robot. (DWAM: Highway Robbery)
 * Scanning slime. (DWAM: Doomsilk)
 * Cancelling out a phonic blast. (DWAM: We Will Rock You)
 * Shattering ice. (DWAM: Arctic Eclipse)
 * Scanning the President of Earth for alien influence. (DWAM: Return of the Klytode)
 * Blowing up a fire hydrant. (DWAM: Creature Feature)
 * Atmospheric excitation to cause rain. (DWAM: Mudshock)
 * Tickling a lion with sonic waves. (NSA: The Slitheen Excursion)
 * Repair an overloading distribution box. (TDL: The Graves of Mordane)
 * Download a journal. (TDL: The Colour of Darkness)
 * Detecting and illuminating ultraviolet characters. (TDL: The Game of Death)
 * Remotely controlling environmental controls. (TDL: The Game of Death)
 * Detecting the arrival of spacecraft. (TDL: The Pictures of Emptiness)
 * Pick up traces of psychic spoor. (DWM: Mortal Beloved)
 * Tinting the Doctor's glasses. (DW: Planet of the Dead)
 * Opening bus doors. (DW: Planet of the Dead)
 * Unlocking handcuffs. (DW: Planet of the Dead)
 * Incapacitate a Gizou. (IDW: Fugitive)
 * Detecting time traces. (SJA: The Wedding of Sarah Jane Smith)
 * As an actual screwdriver, without touching the screws. (DW: Dreamland)
 * Disabling a Shimmer. (DW: The End of Time)
 * Switching the Hesperus' power off. (DW: The End of Time)
 * Changing the course of the TARDIS. (DW: The Eleventh Hour)
 * Opening a "crack" in space-time. (DW: The Eleventh Hour)
 * Overloading all technology in an area (To the point where the screwdriver itself explodes). (DW: The Eleventh Hour)

Mark VII
Following the Mark VI's destruction, the Doctor received a new Sonic Screwdriver from the TARDIS. It was radically different to the previous model, having “claws” and a green diode, rather than blue. It also has copper plating in various places, both of which are similar to the new TARDIS interior. (DW: The Eleventh Hour) This version of the screwdriver was destroyed when a Shark bit it in half and swallowed the top half. In this instance, it was also revealed that this version of the Sonic Screwdriver could repair itself and sent out a homing signal to any parts that had been severed. (DW: A Christmas Carol)

Known uses

 * Scanning Starship UK's engine room. (DW: The Beast Below)
 * As a torch. (DW: The Beast Below)
 * To force a Star Whale to regurgitate by overloading its chemo-receptors. (DW: The Beast Below)
 * Making a Star Whale's voice audible to the human ear. (DW: The Beast Below)
 * Amplifying an electrical beam. (DW: The Beast Below)
 * Opening the chest plate of an Android's controls, (unsuccessfully) attempted to defuse the bomb inside it. (DW: Victory of the Daleks)
 * To increase a signal strength. (DW: The Time of Angels)
 * To scan Father Octavian's computer. (DW: The Time of Angels)
 * To open a mechanical door (unsuccessful when combating the Weeping Angels). (DW: The Time of Angels)
 * Opening the entrance hatch of a space ship. (DW: Flesh and Stone)
 * Isolating the lighting so that the Weeping Angels could not drain the power. (DW: Flesh and Stone)
 * Redirecting all the power to the doors in order to open them. (DW: Flesh and Stone)
 * Determining the nature of the cracks throughout time and space. (DW: Flesh and Stone)
 * To send a signal through to Amy's communicator to help guide her through a forest. (DW: Flesh and Stone)
 * Uploading software. (DW: Flesh and Stone)
 * Simultaneously healing and analysing wounds. (DW: The Vampires of Venice)
 * Sealing doors. (DW: The Vampires of Venice)
 * To open gates. (DW: The Vampires of Venice)
 * Block out the effects of perception filters. (DW: The Vampires of Venice)
 * Detecting where lights are. (DW: Amy's Choice)
 * Exploding lightbulbs. (DW: Amy's Choice)
 * Scanning lifeforms. (DW: Amy's Choice)
 * Scanning piles of dust for traces of children. (DW: Amy's Choice)
 * Unlocking padlocks. (DW: The Hungry Earth)
 * Hacking into computer records. (DW: The Hungry Earth)
 * Displaying energy barricades which are usually invisible to the naked eye. (DW: The Hungry Earth)
 * Activating Bio-programmed soil. (DW: The Hungry Earth)
 * Scanning for heat signatures. (DW: Cold Blood)
 * Disabling Silurian weapons. (DW: Cold Blood)
 * Scanning an infection. (DW: Cold Blood)
 * Locking the TARDIS doors. (DW: Cold Blood)
 * Opening the gate to the London Underground. (VG: City of the Daleks)
 * Opening up a discarded Dalek dome. (VG: City of the Daleks)
 * Bypassing Dalek security seals. (VG: City of the Daleks)
 * Opening up control panels in Kaalann. (VG: City of the Daleks)
 * Accessing the Visualiser eye. (VG: City of the Daleks)
 * Tampering with The Dalek Emperor's casing. (VG: City of the Daleks)
 * Activating a Dalek console trap. (VG: City of the Daleks)
 * Restoring the Visualiser eye's power. (VG: City of the Daleks)
 * Constructing a Dalek Vision Disruptor. (VG: City of the Daleks)
 * Opening Kaalann doors. (VG: City of the Daleks)
 * Heating Water and Ice. (VG: Blood of the Cybermen)
 * Giving a Cybermat a "Cyber-Migrain". (VG: Blood of the Cybermen)
 * Distracting Cybermats. (VG: Blood of the Cybermen)
 * Fixing platform lift control panels. (VG: Blood of the Cybermen)
 * Closing the door to the Cyber-conversion chamber. (VG: Blood of the Cybermen)
 * Unlocking Cyber-conversion unit manacles. (VG: Blood of the Cybermen)
 * Disassembling a Chronon Blocker. (VG: TARDIS)
 * Unsuccessfully attempting to stun the Krafayis (possibly due to being unable to find the right prozactic setting), appearing to please it instead. (DW: Vincent and the Doctor)
 * Opening the door to the Attempted TARDIS. (DW: The Lodger)
 * Changing a Hologram between its different forms. (DW: The Lodger)
 * Scanning Stonehenge. (DW: The Pandorica Opens)
 * Lighting flaming torches. (DW: The Pandorica Opens)
 * Scrambling a Cyberarm's circuits. (DW: The Pandorica Opens)
 * Scanning the Pandorica. (DW: The Pandorica Opens)
 * To open the Pandorica. (DW: The Big Bang)
 * To close and lock the Pandorica. (DW: The Big Bang)
 * Locking the National Museum's doors. (DW: The Big Bang)
 * Amplifying a satellite dish to scan for an exploding TARDIS. (DW: The Big Bang)
 * Locking the National Museum's roof hatch. (DW: The Big Bang)
 * Giving orders to androids. (WC: The War of Art)
 * To reconfigure the binaries in the TARDIS. (VG: Evacuation Earth)
 * To confirm the isomorphic nature of a control panel. (DW: ''A Christmas Carol)
 * As a lure to attract an alien race of fish. (DW: A Christmas Carol)

Mark VIII
The Mark VII was destroyed during the events of DW: A Christmas Carol, however the Doctor states that he'll be replacing it with a new one. This new model has not yet been seen in a televised story.

Known uses
None yet.

Mark ?
In the Doctor's personal future, he had upgraded the screwdriver with, in addition to the Mark VI settings, red settings and damper settings. He gave it to River Song, both for her use and, unknown to River, a Neural Relay, which saved River's Data Ghost for uploading into the main computer of the Library. (DW: Silence in the Library / Forest of the Dead)

Known uses

 * Activating and disabling gravity platforms. (DW: Forest of the Dead)
 * Fixing light bulbs. (DW: Forest of the Dead)
 * Storing the consciousness of a human (specifically River Song's). (DW: Forest of the Dead)
 * Increasing mesh densities to over 800%. (DW: Forest of the Dead)

Related tools

 * Liz Shaw had her own version of the Doctor's "door handle" device, which she used to open the door to the Doctor's shed. (DW: Inferno)
 * Romana constructed her own sonic screwdriver. Her version so impressed the Doctor that he attempted (unsuccessfully) to swap sonic screwdrivers with her. (DW: The Horns of Nimon) She later gave it to the Doctor. (NA: Lungbarrow)
 * This resembled a smaller, slimmer version of the Doctor's Mark II.


 * The Master had a similar tool called a laser screwdriver. (DW: The Sound of Drums)
 * Captain Jack Harkness and later River Song possessed a sonic blaster. (DW: The Empty Child/The Doctor Dances, Silence in the Library/Forest of the Dead)
 * Using stolen and incomplete UNIT design plans, Toshiko Sato created a sonic modulator. (TW: Fragments)
 * Miss Foster had a sonic pen, with a similar design, described as sleek, to the Doctor's sonic screwdriver. It is unknown if it doubled as a writing tool. (DW: Partners in Crime)
 * The Doctor gave Sarah Jane Smith a sonic lipstick, a similar tool. (SJA: Invasion of the Bane)
 * The Doctor mentions that he once had a laser spanner as well but Emmeline Pankhurst took it from him. (DW: Smith and Jones)
 * Mrs Wormwood was in possession of a ring called a Phonic disruptor. (SJA: Enemy of the Bane)
 * The Sixth Doctor defeated Cybermen using a sonic lance, similar in function but designed to work as a weapon as well.
 * Jackson Lake carried what is most likely the most primitive iteration of the sonic screwdriver. His version was a regular 19th century screwdriver which he claimed to be sonic by virtue of it making a sound when it was hit against a surface. (DW: The Next Doctor)

Behind the scenes

 * The tool was retired during the Fifth Doctor serial The Visitation as it was felt it had become overused. It was absent for the Sixth Doctor era and all of the Seventh, except in Doctor Who in which the Seventh Doctor was seen to use it to lock the Master's remains away, and the Eighth Doctor recovered it at the end of the film. The tool was reintroduced with the Ninth Doctor and has become the show's most frequently used gadget besides the TARDIS itself. It has since appeared in many Seventh and Eighth Doctor audio adventures from Big Finish Productions.
 * For unexplained reasons, the Tenth Doctor's Sonic Screwdriver had a green casing in The Infinite Quest.
 * During early production of Series 1 (2005), the production crew decided to switch from their original prop to one based on the toy Sonic Screwdriver because the first prop was prone to falling apart and so the production team secured molds from the toy replica in order to make a more reliable prop for the next season.
 * Early conceptual art of the modern era Sonic Screwdriver feature a different "tube" section, with notes referring to "glowing organic circuitry", and a movable ball-joint on the emitter, to allow use around corners and in tight spaces. Instead of the "glowing circuitry," the actual prop and toy reproductions feature a black "swivel," like a simple helix. When given a personal copy of the concept art, David Tennant himself commented on the lack of the swivelling emitter.
 * Another early piece of concept art, similar to a simple Bitmap drawing, reveals that the black "cap" at the reverse end of the Sonic Screwdriver was intended to be an opening set of "feet," allowing the Sonic Screwdriver to plug into a section of the TARDIS console. This feature was also dropped from the eventual prop model. The "claws" on the Series 5 model of the sonic screwdriver may be a re-imagining of these "feet".
 * There are two main versions of the Mark VI Sonic Screwdriver - one has a slide feature with button, and one which does not slide and has a fixed button. The two prop types varied each episode.
 * The sound effect heard when the Sonic Screwdriver is used is made by a Cork Screw, and then edited to form the signature sound of the screwdriver.
 * A toy of the Mark VII (Matt Smith version) was seen in "Light Echoes", an edition of "The Sky at Night" broadcast on BBC4 on Wednesday 5th October 2010. The screwdriver was (jokingly) used to scan a part of the LOFAR radio telescope, then under construction in Chilbolton, Hampshire, UK.
 * In the original script for The Eleventh Hour, the Doctor referred to the Mark VI Screwdriver as "Level 4000" technology.