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 38mm Bi-directional Offset Provides Extended and Comfortable Eye Relief Ring Distance from Outer Edge to Outer Edge 75mm