Hawke 1-Pc Mount, 1" Rings, 9-11mm Rail, Medium, Matte Black 1-piece mount 1" rings / 25.4mm Medium height - 1.7" / 43mm Reversible dove tail clamp that fits 9-11mm and 3/8 inch Internal cushion tape prevents marks and scope damage High grade anodized aluminum with rounded edges Fitted with recoil stop pin 4.9 oz. 3.9" length Matte black High powered air rifles can deliver punishing recoil which could possible shake a riflescope out of zero. Hawke scope mounts are designed to withstand that powerful recoil.