replacement muzzle for the "1938" model of Daisy Red Ryder bb gun, also sold as the "Adult" model. stabilizes inner barrel for better accuracy, raises sights to work with a trench style picatinny rail (https://www.thingiverse.com/thing:4885923) . DO NO FORCE IT ON, for best results heat both the part and the outer barrel with a heat gun, part should make a perfect friction fit when properly heated.