VERY100 Low Profile 25.4mm Scope Ring Barrel fit 21mm Picatinny Rail Scope Mount 2pcs These are Low Profile Scope Rings; Type: Low Profile(9mm) These scope rings fits on 21mm Picatinny weaver rail mounts Rings are for a solid mount Scope rings are for standard scopes 25.4mm scope tube. These are very high quality scope rings for you rifle, and make an excellent upgrade