Features Specifications: EDGE-USB 108/USB2.0/GSM/GPRS/EDGE/900/1800/1900 MHz ds card EDGE, GPRS and GSM circuit-switched data transmission Data, voice, messaging features Multiplexing to support the application Firmware can be upgraded Plug-and-play, easy to integrate, LED display USB-powered, no external power adapter Operating temperature: -20 ~ + 55 Storage Temperature: -30 ~ + 75 Humidity: