UTG 30mm/2PCs Medium Profile Picatinny/Weaver Rings Precision Machined from Aircraft-grade Aluminum Alloy with Anodized Black Matte Finish. Friendly Hex Screws with Retention Features. Full Length Locking Plate to Guarantee Easy Installation and Secure Fit. Fits All Picatinny/Weaver Rails Great Quality at Most Affordable Price.