GSM Alarm System: 1. Host one (including antenna) 2. Wireless door ... the user can be pre-recorded 10 seconds alarm voice alarm voice broadcast.2, the host can set the ... time.3, host on-site monitoring, intercom functions: Alarm may duplex intercom for field personnel.4, 16 ... surrounding zone, internal zone, 24-hour zone, sound alarm, silent alarm types for different occasions.5, cable zone (normally ...