Description Description Schlage 8440 MIFARE DESFire Clamshell Smart Cards, formerly aptiQ 8440, feature 13.56MHz 13.56 MHz frequency that utilizes high security encrypted data which is mutually authenticated in communication between the card and reader. When ordering MIFARE DESFire format credentials, you will need to provide the facility code (excluding 32-Bit and 37-Bit) and a unique start serial number (excluding 35 Bit) to be programmed. Memory: 4K byte / 32k bit memory / ISO 14443 Bit Format Options: 26-Bit, 32-Bit, 34-Bit, 35-Bit, 36-Bit, 37-Bit, 40-Bit, 48-Bit Facility Code Range: 0-255 (For 26-Bit) - Other Bits vary Number Range: 0-65,435 (For 26-Bit) - Other Bits vary Your facility code and current serial number range can typically be found on the label of the latest box of credentials you have. For assistance finding this information for ordering, please contact us. Request a quote for special high volume discounts.