This is a 1" tube scope mount for your Benjamin HB22 pellet pistol. If you're looking to attach an old timey scope to an old timey pellet pistol to squeeze a little more accuracy out of it like I was then this is a decent way to go. I imagine this would also fit the Crosman 22cal air pistols. It uses (2) 1/4" bolts and I got a nice rigid mount printing w/ 5 layers and 25% fill.