This is an affordable tire deflator replacement that replaces your finger. Screw them (there are 4 of them in the kit) onto all four tires at once if you like. There is no set stop point control valve, but they inflate your tires slowly enough for you to keep an eye on them. There is a thread on the top for attaching a manometer and checking the pressure while driving. Cozy. Supplied with 4 deflators, key fob and nozzle, o-rings and 8 plugs.