... .Touch keypad, blue back-up light, blue LCD display date, time and current armed status2.With built-in antenna sensors like ... keypad(optional),remote controller,and phone call9.Available in AC/DC low voltage alert10.Press-to-learn sensors to alarm host ... <500mA Backup battery:Lithium 3.7V/800mA(Rechargeable) Standby time<16 hours, charge time> 12 hours GSM frequency: 2-band(900/1800MHZ) or ...