Add-on module for your Arduino mainboard mainboard not supplied Operating voltage 5V supplied from an Arduino board Supports Micro-SD cards Socket for wireless expansion modules Once youve bought your first main Arduino board its time to start adding additional functionality with the use of extra modules referred to as shields. The Wireless SD shield allows an Arduino board to communicate wirelessly using a wireless module. It is based on the Xbee modules from Digi but can use any module with the same footprint. The module can communicate up to 100 feet indoors or 300 feet outdoors with line-of-sight. It can be used as a serial USB replacement or you can put it into a command mode & configure it for a variety of broadcast & mesh networking options. The shields breaks out each of the Xbees pins to a through-hole solder pad.brbr Included on board is a Micro-SD card slot. When using the SD Library to access the card Pin 4 is CS & cannot be used otherwise. SPI also relies on pins 11 12 & 13 for communication. Also on board is a switch allowing for control via USB (Universal Serial Bus) or the microcontroller.