M1Surplus Dovetail Adapter Rail Mount - Made from durable Aluminum Material, Matte black color, This adapter allows you to convert your 3/8" ( 11mm ) dovetail equipped rifle to accept industry standard 7/8" Weaver and Picatinny style scopes or accessories. The 3/8 dovetail is very common on many rim fire rifles. With this adapter you can equip your rifle to accept modern accessories that use a Picatinny or Weaver type interface. Provides a 3.94 inch long Picatinny style rail with cross slots. Top mounted allen head set screw acts as a stop pin to prevent movement. Easy installation requires no modifications. Brand new item