Precision Reflex 30mm Aimpoint Non Adjustable Ring High 1.175in Black. 175in constructed of T6 6061 hard coat black anodized aluminum. Top cap is constructed of steel for maximum holding power is held in place with (4) #6-32 screws. Specifications for Precision Reflex 30mm Aimpoint Non Adjustable Ring: Manufacturer: Precision Reflex Color: Black Finish: Anodized Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Fabric/Material: T6 6061 Aluminum Tube Diameter: 30 mm Red Dot Sights-Footprint: Not Applicable Optic Cut: Aimpoint T1 Length: 1 in Condition: New Package Contents: Precision Reflex 30mm Aimpoint Non Adjustable Ring Precision Reflex 01-0031: 30mm Aimpoint Non Adjustable Ring High 1.175in Black