Smittybilt’s automatic tire deflators, sold as a set of four, make airing down for your off-road adventures quick and easy. Simply set your desired tire pressure, screw them onto your valve stems, and let the deflators do the rest, automatically shutting off when the correct pressure is reached. The set includes a storage bag and extra valve caps for convenience. *Note: Designed for off-road use only. Always set proper tire pressure for on-road driving safety.