If you aready have a DC accessory power bus and want to run SwitchWrights you can use this board to down-shift the DC voltage to 5V with a high efficiency. Whereas a 7805 regulator is only 40% efficent converting 12V to 5V, this board is 80-90% efficient. This puts a smaller load on the accessory bus for each SwitchWright added. The board will run 20-25 SwitchWrights and has 8 output positions (multiple SwitchWrights can be connected to each position). The bottom of this board acts as a heatsink so it should be elevated a small amount to form an air gap.