Voltoscope

Voltoscopes were beams of energy fired from hoverbouts that the Daleks used to trap Terrorkons after many had attacked a weapons installation the Daleks had built on Skaro. (COMIC: The Terrorkon Harvest)

In an alternate timeline, voltoscopes were on display in a museum in the Tower of London. (AUDIO: Jubilee)

Behind the scenes
A Voltoscope was also listed in The Dalek Book where it was described as a small arms device. The description explained further:
 * "This is a transistorised torch. Into the size of a normal torch, they have concentrated the power of a thousand suns. This flashed into the eyes of an advancing enemy, creates temporary blindness. Imagine having a huge searchlight being shone straight into your eyes and you have some idea of the intensity of the beam."