In the seventh season two-part episode Gambit, mercenary captain Arctus Baran wore this device on his belt, and with a touch of the black switch, could inflict a varying amount of pain on anyone implanted with a neural servo, including his pirate crew; archaeologist 'Galen' Picard; and renegade Starfleet Commander Riker.
Resin and acrylic, illuminates as seen onscreen, velcro attachments across the back.
From Profiles In History.
