Quad-band GSM/GPRS 850/900/1800/1900 MHz 
Separate RS-232 and RS-422/485 serial interfaces (G2150I only)
2.5 KV RMS isolation for 1 minute for all serial signals (G2150I only)
Extended operating temperature from -30 to 75°C (G2110-T only)
LED indicators for GSM/GPRS, data transmission, and signal level
DIN-Rail and wall mounting
SMS Tunnel Mode provided