... ,Update firmware by local or internet7,Field proven compatible with Asterisk-based softswitches ModelSinoV-S504GSinoV-S508GNumber of Channels4GSM8GSMFrequency850/900/ ... Supply100-240VAC, 50 - 60 HzDimensions·Rack mountable 1U chassis(compatible with 19" Rack)·Width: 260mm·Height: 40mm·Depth: 170mmWeight1.5kgOperating ... support CDMA/WCDMA ,you need order SinoV-X500 type. 4 Port Wireless GSM Voip Gateway