The HAA85BL is a self-contained security keypad and is a reliable and cost-effective solution for residential and commercial installations. It is compatible with virtually any electric locking device and can be used as a control for security systems, automatic operators and machinery. Over 100 million combinations are possible for the user codes (multi-user mode). Programmed data stored in the system is non-volatile. Comes with tamper switch and plastic case. Audible key operation.