Milled from barstock, these rings provide the solid strength required for harsh field and tactical use. With four TORX screws per cap, the scope is securely locked into the ring to prevent recoil movement. Large, 1/2" hex nut lets you torque ring securely to any MIL-STD 1913 Picatinny base, and helps achieve a consistent return to zero. Steel cross lug provides additional strength, prevents shifting caused by recoil. Mfg: Nightforce SPECS: Steel, parkerized, matte finish. 30mm I.D. 5/8" (15.9mm) wide. Height measured from top of base to bottom of scope body: Low – .300" (7.6mm), High – .535" (13.6mm). Extra High – .782" (19.9mm). Fits Picatinny bases.