Leupold PRW2 1in Steel Scope Rings - Low - Leupold 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. 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 Bases are available for many popular rifle models 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