The 19300 Tire Valve Stem Wrench from Schley Productsis designed for work on medium and heavy duty Class 7 and 8 trucks. According to Schley, the wrench was made with precise bends, handle length, and 9/16" socket configuration to allow the user to quickly access the valve stem nut on the inner wheel when servicing trailers and trucks equipped with dual wheel setups. The wrench is made with heat-treated forged alloy steel for added strength.