Outfit your semi truck to be Ready for the Road Ahead with properly inflated tires, with the X-tra Seal 3-1/2" Nickel-Plated Tire Valve Stem. Thanks to its sophisticated design, this replacement stem allows operators to add or remove compressed air in the case of leaks or over pressurization. Built with a robust cap to prevent damage to the metal stem. FleetPride is your First Click in Heavy Duty .