The Konus mounting rings for Weaver and Picatinny rails are made from aircraft aluminum and are supremely versatile because they are able to accommodate both the 30mm or 1? scopes by adding or removing the internal ring they come complete with. The Konus #7237 has a dual reversible base that will fit the .22 rail as well.UNIVERSAL MODEL 1" -30MM DUAL USEADD OR REMOVE THE INTERNAL RINGS IN ORDER TO SWITCH FROM 1" TO 30MM DIAMETER2 INTERCHANGEABLE MOUNTS FOR .22 CALIBER AND WEAVER/PICATINNY RAILALL MODELS WITH RECOIL-STOPINTERNAL ANTI-SCRATCH PADDINGSTRONG ANODISED ALUMINUM