Xbee Wireless Kit by Sparkfun Kit allows for simple serial cable replacement Modules support data rates up to 115200bps DIN and DOUT pins of XBee can be connected to either the UART pins or any digital pin on the Arduino (D2 and D3 default) 3.3V power regulation and level shifting on-board 12 x 11 grid of 0.1" spaced prototyping holes