The cyberjammer is a highly illegal piece of equipment. It is a focused electromagnetic transmitter, designed to lock on the operating frequencies of a particular cybernetic equipment. If you know the operating frequency of an implant (easily found out by using a
Cyberscanner), you can target the implant with the jammer and disable it for up to two turns.
The concentration required to jam an implant is significant and you must remain concentrated on maintaining the jam. This gives you a -2 modifier to all actions during these turns and should you be injured during the turns, your concentration breaks.