The GM Twin Fueler Electronic Control Box controls your second high pressure fuel pump, allowing precise rail pressure control with the Twin Fueler Fuel system. The Twin Fueler Electronic Control Box is a completely Plug and Play installation. Simply connect to your factory fuel control actuator(FCA), connect to the second high pressure pump FCA and supply battery power and ground. This will allow the Twin Fueler pump to control pressure, giving better drive-ability as well as the added power when desired!