OmniClass key fobs are compatible with OmniClass readers, a range of 13.56 MHz contactless secure smart card readers that offer superb reliability, consistent read range, and ease of installation. They are available in several sizes and each OmniClass reader incorporates smart card technology allowing the user to support biometric profiles and multiple applications on each card simultaneously. Card numbers for OmniClass/iClass credentials are safely stored and transmitted using 64-bit authentication key encryption, which is suitable for most access control applications. A higher level of security can be achieved using the AES encrypted iCLASS SE/iCLASS Seos and MIFARE DESFire EV1 credentials. Additional keypad versions are available for dual authentication. Card numbers are printed on the OmniClass cards/credentials. MIFARE card serial numbers (CSN) also supported. Interoperability between vendors and applications is possible via the smart card's accessible memory.