Designed to fit onto most 1” diameter shotgun magazines tubes. This will allow you to attach multiple weaver & picatinny style accessories flashlight, laser, bipod etc to your shotgun at any of the 5 angles that the rails provide. Fits most pump shotguns Remington Winchester Mossberg etc with a gap of 35mm. 35mm long This can also be used on accessories like 1" flashlight and laser bodies, or 1" scope tube body (without objective lens bell housing as this can only be slid on to body). +++ SILVER available on special "request", 3 day delay and an extra $9.