The DSI-ES4200-K1-T1 is a door management alarm that monitors for propped doors and door intrusion.Audible, local warning alarms help reduce false alarms caused by doors that are held open. The unit can work as a stand alone alarm or in tandem with access control systems. The alarm timer and sounder volume is field selectable based on the users personal preferences. Installation is easy.The DSI-ES4200-K1-T1 comes equipped with a double bit reset/bypass key switch and a tamper switch. Also known as -DSI Systems - ES4200-K1-T1 - Dr Mgmt Alarm Dbl Bit W/tamper