1,fast sending sms 2,RS232 & USB & RJ45 3,800/850/900/1800Mhz 4,software support ... as a single channel modem. It uses the development of WAVECOM module, 220V power supply, can be a long time stability ... to send text messages. Key Features♦USB/RS232 GSM modem pool♦Based on Wavecom industrial modules Q24plus,Q2406,Q2303,Q2403♦GSM: 850 ...