The ALARM-LOCK-PDK3000-MS is a metallic silver weatherproof access keypad with proximity reader that operates main and auxiliary relays, and can be used to trigger a door strike, an electromagnetic door lock, or any other relay-activated device.In a typical application, the PDK3000-MS will energize its Primary/Entry Relay upon the keypad entry of a valid user code. The relays used in the unit are of the three contact Form C type, containing a Common, Normally Closed, and a Normally Open contact.