Bumlon Rail Mount Dovetail Weaver Tactical Scope Adapter 11mm- 20mm Material: aluminum alloy Fits dovetail 11mm rail. Dovetail to Picatinny rail adaptor for firearms equipped with 11mm or 3/8 inch dovetail standard rails Picatinny rail allows for the mounting of Picatinny or Weaver standard scopes, red dots, magnifiers, or other optics Rail adaptor installs easily via dovetail mount and one vertical stop pin