Leupold Mark 4 Base Mark 4 tactical bases and rings are the strongest of all Leupold mounting systems The one-piece base features a built-in 15 MOA or 20 MOA slope for long range shooting Both 6-48 shoulder screws and the larger 8-40 screws are included to accommodate high recoil applic Strong 1/2" keeper nuts lock the rings solidly against the one or two-piece bases, or any Picatiny- Specifications: - Finish: Matte