... , LCD and functional Buttons.Functions & Features of the GSM Alarm System1)GSM Frequency: Dual-Band(900/1800MHz), Quad-Band is optional ... out the home, the delay time is editable by user;10)Equips with 1 Alarm-Link output relay, once the system triggered, ... internal rechargeable battery which can last 12 hours;18)Based on the GSM communication network and Operation Menu Display technology, apply ...