6 Layer Apron Chaps from STIHL are made from rugged, 400-denier nylon and feature the same UL classified protection as our other chaps. Just snap them over your pants and youre ready to go. Sewn into the legs of the chaps are six layers of Avertic Pro by Engtex, a cut-retardant material designed to clog the sprocket and stop the saw chain on a gasoline-powered chainsaw in case of accidental contact with the rotating saw chain. The open-back design of these chaps makes them a great choice for hot working conditions.