... a year by trained o GSM Alarm Receiver, Link Between Your Home and The Police Station Model: R-2005GSMAlarm Systems send alarm ... with ADEMCO CONTACT ID , ADEMCO 4+2 Express, ,3/1,4/1 communication protocols, adding Caller ID support. The receiver can work ... PSTN (telephone line) and GSM cellular for alarm receiving.Compatible with Contact ID, ADEMCO 4+2 Express, ,3/1,4/1 ( 10-40BPS ...