Agony inducer
From Wookieepedia, the Star Wars wiki.
Agony inducers were small devices used as instruments of torture. They were circular in appearance and could be attached to the ear, where small buttons could be pressed to manipulate the type of agony felt by the subject. The bounty hunters, Fud and Dafi were known to use this instrument. A short time after the Battle of Yavin, the hunters used an agony inducer on the Lepi smuggler Jaxxon in order to force him to tell them the location of Aduba-3.
