Sportsmatch HOP40C 30mm Tube 1 Piece Double Clamp Mount 56mm Please ensure these mounts will suit your application by carefully checking that the tube size and base type is correct before purchasing. 1 Piece Mount. Base Fitting: 9.5 - 11.5mm (3\8") Dovetails - Most popular size (suits most modern airguns & .22 rimfire rifles). Tube Size: To fit 30mm diameter body tube scopes. Front Lens Size: Up to 56mm - This figure describes the maximum size of the objective (front) lens the mount is designed for when the dovetails are flush with the barrel. Please bear in mind scopes with front PX adjustment will often need higher mounts. Bolt Type: Allen Key bolts - Allen Key(s) Supplied. Clamp Design: Double Clamp (four bolts on each cap). With removeable recoil stop pin.