The small device had a small microphone and a camera, both invisible. The badge was small enough to avoid 'arousing suspicion' and could be clipped on clothing to turn people into walking surveillance equipment, all the received infomation was stored in Hyperbrain and was used to track down Dinah Hunter.
The badges where shipped out using vans to those in power then properly to the general population. The hand logo appears everywhere and becomes almost like a flag for the Headmaster's regime.
The badge's design was also its downfall, upon discovering that saying 'complete nonesence' would set Hyperbrain into overload, Lloyd instructed all children troughout the country to speak nursery rhymes into them. As the badges were linked directly to Hyperbrain it couldnt handle data it couldnt understand and turned its hologram off to conserve itself.