The electric fuel pressure gauge comes with its own sending unit. Our BBK adjustable fuel regulator already had an empty port for just such an occasion. Most billet-style regulators usually come with this but it you don't have one, you can always connect it to the Schrader valve on the fuel line. Once the wiring and sending units are hooked up properly, turn the key to verify that the instruments perform their auto-zero feature. This recalibrates the gauge every time you start the car.