Ruger Clam Pack Single Ring Medium 30mm Diameter Hawkeye Matte Blued. Rings are made of alloy or stainless steel and are available to fit 1" or 30mm tube diameters. Finishes include stainless matte blued or Ruger's signature finishes of Hawkeye Matte stainless Hawkeye Matte blued or Target Gray stainless. Specifications for Ruger 90321 Clam Pack Single Ring Medium 30mm Diameter Hawkeye Matte Blued: Manufacturer: Ruger Finish: Matte Ring Height: Medium Tube Diameter: 30 mm Ring Quantity: Single Ring Type: Ring Single Condition: New Package Contents: Ruger 90321 Clam Pack Single Ring Medium 30mm Diameter Hawkeye Matte Blued The Ruger 90321 Clam Pack Single Ring Medium 30mm Diameter Hawkeye Matte Blued is a quality addition to the Ruger lineup. For more great deals on Riflescope Rings by Ruger please browse our Ruger Riflescope Mounts Rings & Bases page. Ruger 90321 Clam Pack Single Ring Medium 30mm Diameter Hawkeye Matte Blued