This is the genuine Crosman/Benjamin valve-stem original to Discovery and Challenger rifles. It also fits the 22XX CO2 valves in 2240, 2250, 2260, 2300KT, 2400KT and related models for bulk-fill, PCP and tank-block conversions, which also require a bulk-fill/PCP valve cap and an upgraded valve screw/screws. Refer to our listings for those parts for more info.