Re:Back-compat? (Score 1)

No, this is an active jamming device, and as the other readers indicate, may only work at a particular frequency or communications protocol. However Smart Tools offers an RFID Shield - a passive device that prevents your RFID card from being detected or communicating, and is independent of frequency or protocol. There's info and a picture at: http://smarttools.home.att.net/rfshield.htm