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