Body Material: High quality 6061 aluminum.Packaging Details:2 x rings,1x allen key.
The scope rings are designed for most diameter 1''(25.4mm) scopes.scope ring is secured with wider double screws for extra strength. for Picatinny Rail (21mm).
Design in hollowed-out configuration between the ring and the bottom of the base, to release heavy duty when clamping your scope.
Built-in tape inside per rings to prevent from marring the scope, also prevent sliding and holding postion accurately.
Come with a L wrench, you can tighten the top four screws with it. Then just twist off the below nut by hand,and mount the base on 20mm rail easily.