Soft tip and slider along with anodized tube for no-mar, chemical resistant toughness. Spring loaded for a snug fit performance preventing chemical leaks at the bore. Comes with three contoured tips for fit and function superiority and a deeper seat in the bore. Designed for .22CF to .375. Locking keys hold guide in place in most bolt action of AR style firearm. Tips are polypropylene for tight fit and chemical resistance