A&E Hand Tool offers their Serpentine Belt Wrench for Heavy-Duty Trucks, No. 8593, a 13" long chrome-plated wrench that is used to release any serpentine belt tensioner with a 1/2" square drive opening. This made in the U.S.A. tool features ratcheting action for better positioning, ergonomic vinyl grip and a 1" reversible ratchet head.