Arduino shield with a socket for wireless modules like Digi Xbee, Bluetooth, RFID or Wifi Modules. Built in 3.3V voltage regulator, active voltage translators and prototyping area
It comes with a microSD socket you can use with SD library to save and load data. If it is used, CS pin won't be available (used by library). It also includes a switch to select how to communicate with the module (USB/Board) instead of jumpers.