SIMCOM SIM800L V2.0 GSM/GPRS Module is a QUAD BAND GSM/GPRS module which compatible with Arduino. The module works to add both of GSM features (voice call or SMS) and GPRS features. The advantages of these modules are the VCC and TTL serial levels that have 5V voltage, so you can directly connect it to Arduino or other minimum system with 5V of voltage level. There are so many GPRS/GSM modules on the market which need to add 5V regulator and level converter circuit, while SIM800L V.2 GSM/GPRS module already has a built-in regulator circuit and TTL level converter on the board.Here is just an example project using SIM800L V.2. It’s about how to control relay using SMS controller. You can easily turn-on or turn-off many objects in your house, such as lamp, fan, and etc.”