Steelman Socket Set consists of five (5) sockets with nylon sleeves, including the 3 most popular metric sizes (17mm, 19mm, and 21mm) and the 2 most popular SAE sizes (13/16" and 3/4"), color-coded for easy identification. These sockets are constructed of chrome-moly steel with polypropylene inserts to prevent damage to lug nuts and wheels, designed not to damage or scratch chrome, powdercoat, anodized, cadmium, paint, or phosphate-coated fasteners.