Clara Oswald's vortex manipulator

After Clara Oswald located the Twelfth Doctor in Essex in 1138, slapped a vortex manipulator on her. Slaved to Missy's own, the device allowed Clara to travel with Missy to Essex.

When Clara was fired upon by Dalek control, (TV: The Magician's Apprentice), the manipulator used the energy from the gunstick blasts to recharge and teleport Clara to safety, although Missy noted that this had destroyed its functionality. (TV: The Witch's Familiar)