1,fast sending sms 2,RS232 & USB & RJ45 3,800/850/900/1800Mhz 4,software support 5,serial port gsm modem The device built-in ... x 200mm♦Weight: 5.0kg serial port gsm modem Product Feature1, can insert 16 SIM cards(big or small)2, connection with ... ♦Oil Company ( other chain business model)♦Government agencies or large township serial port gsm modem Supported Operating Systems: All popular 32-bit ...