Fantastic quality mounts. These mounts are to fit 1" diameter tubes These mounts feature a recoil stop to stop your scope creeping under recoil and cushion tape to prevent damage to the riflescope tube. - removeable if you prefer The precision machined dovetail clamp rail fit snugly onto the rifle dovetail. The dovetail clamp rail fits 9-11mm standard air rifle receivers. During manufacture all the sharp edges are rounded to prevent the accidental pinching of the riflescope tube.