... GSM ALARM SYSTEM(BL2000)Mainly used in House,office,Factory/Hot sale with lowest price! Wholesale & Retail Main Function:8 wireless ... the alarm function of cutting telephone line.With standby rechargeable battery.When the system alarms, it can report and follow up ... GSM ALARM SYSTEM(BL2000)Mainly used in House,office,Factory/Hot sale with lowest price! Wholesale & Retail