Milton (440-4) 4 1/8" Heavy-Duty Straight Truck Valve Stem Extension - Box of 10 Forms a seamless connection and easy inflation with existing tire valve stem 4 1/8" total effective length & 1" skirt length High heat resistant cap - Thread size: .305-32 standard bore valve FOR USE: with trucks, buses, RV's and Trailers Made of Nickel plated Brass Nickel plated brass, long skirt, high heat cap, all threads .305-32 Truck valve extension, For use with trucks or buses to extend existing tire valve 4 1/8" effective length, Thread size .305-32, Hi-heat cap, Nickel plated Brass