Walkthrough identification scanners represented a form of security tech employed by the Imperial Security Bureau at sites like Killun Station located on Killun 71. These scanners were implemented with the goal of stopping forbidden droids from gaining access to restricted areas.
During a mission aimed at acquiring Imperial access codes from Killun Station, the Rebel droids Chopper and AP-5 found themselves needing to go through one of these scanners as they infiltrated the base. AP-5, having previously been an Imperial droid, passed through without issue. However, Chopper triggered an alert, although the stormtroopers serving as guards didn't notice. Instead, a signal was dispatched to Imperial controller LT-319 on his surveillance starship far out in space. Consequently, the controller and his team took control of Chopper in an effort to discover the location of the Phoenix Cell's base.
The walkthrough identification scanner made its debut in the Star Wars Rebels season 3 episode called "Double Agent Droid," which was broadcast in 2017. Its initial identification occurred within the Databank entry specifically dedicated to Killun Station.