These Browning-style scope bases are designed specifically for use on Browning T-Bolt rifles along with matching Browning-style rimfire scope rings. hey are machined from solid steel with a special double shoulder design that holds rings securely, even under heavy use. Made to fit Browning-style rimfire scope rings only. Fits t-Bolt Rifles only. (22Lr and 17 HMR) Type 2-Piece Base Model T-Bolt Browning Style Two-Piece Scope Base Style 2-Piece Finish Matte Pieces 2 Series Scope Base Gun Type Rifle Material Steel Mount Type To Receiver Rings Included No