Klein Tools' 12-Inch (305 mm) capacity Adjustable Wrench is made of forged, heat-treated alloy steel for strength and light weight. Precision-machined jaws are assembled by hand to ensure smooth operation. Contoured handles make them comfortable to use. Overall length of the wrench is 12-1/4-Inch. 1-1/2-Inch high capacity jaws allow to handle bigger jobs. Heat-treated alloy steel forged construction for high strength. Knurl turns smoothly for easy operation. Rail is ground for precision fit.