Portable prison cell

Small enough to fit in the palm of a human hand, when thrown on the floor or the ground, the portable prison cell generates a force field around its "prisoner". It depends on a battery of some sort and uses up the power within an hour. At least one of these was owned by Torchwood Three. (TW: Day One)


 * The force field generated by the portable prison cell resembles that of the Chula tractor beam.