SainSmart GPRS+GSM SIM300 Module+Dev.Board V2+Voice adapter+Code The SIMCOM SIM300 Module is AT Command - controlled GPRS+GSM module, via Serial Port (RS232/TTL communication). SIM300 is a Tri-band GSM+GPRS engine that works on frequencies EGSM 900 MHz, DCS 1800 MHz and PCS1900 MHz. SIM300 provides GPRS multi-slot class 10 capability and support the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. The SIM300 integrates the TCP/IP protocol.Support Arduino! To Send/Recieve/Read Text Message, Dial/Answer Phone Call, Fax, etc.