UTG Pro 30mm/2PCs High Profile P. O. I Dovetail Rings Features: - High Profile Precision Optics Interface (P. O. I) Scope Rings Have a 37mm Center Height to Fit 30mm Tube Optics with up to a 73mm Outer Objective Diameter - The innovative Precision Optics Interface (P. O. I) Addresses 3 of the Most Critical Areas in Scope Rings - a) Progressively Machined and Precise Inner Diameter to Achieve a Seamless Interface Between the Scope Ring and Tube b) Torn Screw Locking Side Plate Controlled by Dual Spring Loaded Guide Rods Precisely Clenches Dovetail Rail for a Secure and Repeatable Zero Hold c) Removable Threaded Recoil Stop-pin Provides an Additional Interface Point with the Dovetail Rail for Added Security Against Bidirectional Recoil - Original Snag-free Contoured Profile with Reduced Weight and Size - 6061-T6 Aircraft Aluminum and Steel Construction with a Matte Black Finish Includes: - 2 Piece Ring Set - Each Equipped with 4 Top Torn Screws, Mounts onto Most Dovetail Rails Specifications: - Color/Finish: Matte Black - Material: Aluminum - Weight: 2. 7 oz. - Pieces: 2 - Rail Type: Dovetail - Profile Level: High - Ring Diameter: 30mm - Ring Width: 22 mm - Max. Scope Outer Dia. : 73 mm - Screws Per Ring: 4