This is the LilyPad Arduino USB board, controlled by an ATmega32U4 with the Arduino bootloader. It has a built in power supply socket and an on/off switch with the only extra piece of hardware you need to program the LilyPad USB is a micro-USB cable, since the new IC has built-in USB support. Any of our LiPo batteries can be plugged right into the JST socket to provide you with easy, on-the-go power. That LiPo battery is even rechargeable through the board, no more special external LiPo chargers required!