Leupold QR 1-Piece Base for Thompson Center Contender Rifle, Gloss Black

With Leupold Quick Release steel bases you can mount a scope, zero it, remove it, reattach it and remain nearly dead-on with your original point of impact. The key is precise machining of the patented lever mechanism. Turning the lever forward engages the base of the ring, pulling the ring down and forward, locking it into its "zero" position.