... to Alarm systems to realize wireless alarm(for security use)6) Strong signals,high gain antenna 7) Support SIM card ... , Front Picture with Antenna connection D, Bottom side picture Specifications: 1) Air interface standard: GSM850/1900Mhz,900/1,800Mhz phase 2+ full band 2) ... Dial tone frequency:450MHz(standard) 9) Surrounding temperature: -10°C ~ +40°C10) AC power: DC 10V - 20V 11) Input: AC100 - 230V, ...