UTG 30mm/2PCs Medium Profile Airgun Rings w/Stop Pin Precision Machined from Aircraft-grade Aluminum Alloy with Anodized Black Matte Finish. Complete with Stop-Pin for Rock Solid Application. Ring Base Designed with Locking Hex Screws to Tightly Fit on Mounts with Airgun/.22 Dovetail Dimensions. Reversible Locking Plate to Fit Full Range of Airgun/.22 Rails Great Quality at Most Affordable Price.