Leupold PRW2 1-in Medium MountsWeight - 6.2 ozHeight - .85Ring Diameter - 1Finish - MatteWe?ve updated the proven cross-slot design of these steel rings to be stronger and to give them more contact with the base for added stability and easier installation.Features:PRW Rings - Steel rings that are based on the proven cross-slot design provide permanent cross-slot stability. Uses the Leupold QRW bases or any other Picatinny-style mounting rails.Cross-Slot Base Rings - Our cross-slot base rings are engineered specifically to match up with cross-slot bases. We recommend you mount these incredibly stable rings on firearms such as tactical shotguns with built-in mounting rails.Bases for many popular rifle models available (mounts)