This shield allows you to use a computer power supply (or other power source) to use your Arduino to switch high current. With RFP30N06LE MOSFETS, you can easily control a lot of current directly from your Arduino. Project description, more information and ordering can be found at https://www.sparkfun.com/products/10305 Datasheet: http://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf