1,2.45GHz Active keychain tag 2, active RFID tag, RFID long range read tag 3, RFID active key FOB tag 2.45GHz Active ... keychain tag, active RFID tag, RFID long range read tag, RFID active key FOB tagPerformance:l MR3821A is a ... ceil, 1 year life time. The battery can be changed. RFID active keychain tag