Primary Arms Classic Tactical Rings 30mm Body Single Lower 1/3 Cowitness Extra High Black. 59 inches above your 1913 Picatinny rail or Weaver rail platform. One ring is included held together by six Torx head screws. Constructed of high quality aluminum with a matte anodized finish this ring features a lifetime warranty. Specifications for Primary Arms Classic 30mm Tactical Ring - Extra High: Manufacturer: Primary Arms Finish: Anodized Matte Tube Diameter: 30 mm Gun Model: AR-15 Ring Quantity: Single Quantity: 1 Fabric/Material: Aluminum Condition: New Color: Black Objective Lens Diameter: 30 mm Mount Type: Picatinny Package Contents: Primary Arms Classic 30mm Tactical Ring - Extra High Primary Arms Classic Tactical Rings 30mm Body Single Lower 1/3 Cowitness Extra High Black 910068