... :have two way communication with you via text and audio over the mobile phone network. With this gsm ... the recorded voice at first, call six phone numbers and send the short message (SMS) 6. The SMS ... sensors, gas sensors, smoke sensors, beams, panic buttons and so on, 160pcs in total. 11.Send the SMS ... to program, it is very easy and quick to be installed and operated 12. With inner back-up ...