Heavy duty 30mm steel rings, machined in pairs, serial numbered, and designed specifically to securely hold large, heavy scopes on hard-recoiling guns. Weaver-style clamp with big A 1/2" nut really snugs ring to the mount. Ultra-High provides optimum height for AR-15, AR-10 and SR-25 rifles. Mfg: Badger Ordnance SPECS: Black Matte finish. Ring height measured from top of mount to center of ring; Standard - .823" (2cm), Medium - .885" (22.5mm), Medium High - 1.0" (2.5cm), High - 1.125" (2.8cm), Ultra High - 1.378" (3.5cm). Weights; Standard - 6.6 oz (187 g), High - 9 oz. (255 g),