The perfect shop hammer! Designed and built specifically for bicycle work The HMR-4 has a fiberglass shaft, a soft touch rubber grip, and a two-sided head-steel on one side and a replaceable plastic head (part #293) on the other side 13.5" long (345mm). Steel striking face: 1-3/8" (35mm) diameter Plastic face: 1-11/16" (43mm) diameter 24 ounce head (680g)