... 2. Phone book & Whitelist & Blacklist 3. Sending & Receiving & Storing SMS 4. Maximum 16 wireless sensors 5. Password supported 6. Wireless 433 or ... voltage Protection:Activating time≤ 1sData Response Time:≤ 10s (under normal GSM network status)Working Voltage & Current:7.5-12V, 1. ... ,school,library,bank,financial office,office,computer room. 2012 GSM home phone Multi-functional Telephone Alarm System