Akuvox Compact Security Relay Single Door I/O Module (SR01)The Akuvox SR01 provides secure door control via encrypted communication when combined with other Akuvox devices. The module with ultra compact form, easily placed in most standard installation boxes, is installed on the secure side of the door. If anyone attempts to dismount or vandalize the door station, SR01 cuts the connection to the door strike and the door remains securely locked. Environment: Indoor 1 button, for pairing Plastic casing