... B.Rear picture C, Front Picture with Antenna connection D, Bottom side picture Specifications: 1) Air interface standard: GSM850/1900Mhz, ... 960MHz Ii) Reception: 1, 805 ~ 1, 880MHz 3) Channel space: 200kHz 4) User line, bell signal: In line with GB/T15279 5) ... D. Work with billing systems for public phone useE. Work with alarm system for security purpose GSM Transmitter, GSM FWT with 1 Year Warranty