DoorBird A8005 Dual-Frequency RFID Transponder Key Fob, 125 KHZ (EM4100) and 13.56 MHz (MIFARE® DESFire® EV2 8K), for D21x and later. (10 pieces) Click or scroll to zoom Tap to zoom by DoorBird SKU DBA8005 This website is for Authorized Dealers only. Pricing and checkout is disabled unless you are authorized. "Login" or Click "Dealer Application" to apply. DoorBird A8005 Dual-Frequency RFID Transponder Key Fob, 125 KHZ (EM4100) and 13.56 MHz (MIFARE® DESFire® EV2 8K), for D21x and later, 10 pieces