Features: Number of Quad Band GSM channels per module: 1GSM External antennas: 1 SIM Cards: 1 External power supply required: No Interoperable modules: 4FXO 4FXS 2FXOS 4BRI 1E1/T1(PRI) Supported protocols Voice (2G) SMS Accessibility – Through Asterisk 1.8x Temperature: Humidity: 5% ~ 95% Non-Condensing Physical Dimensions – 30 x 51 mm Certifications – CE / FCC / RoHS