Fully machined from 17-4 PH heat treated stainless steel billet. Each lug is precision surface ground then put through a three point thickness inspection to verify a uniformity of +-.0001 or better before leaving the factory. Lug is 0.250" thick. Features tapered sides and rounded corners to prevent damage to bedding during removal and installation. Mfg: Precision Armament SPECS: Material: 17-4 PH Stainless, H900 Hardened, 44-46 RHC. Finish: Precision Surface Ground faces, Matte blasted walls. Height: 1.8". Width: 1.3125". Bore: STD: 1.065" . Thick: STD: 0.25"