Luth-AR, .750, Adjustable Gas Block, Black NEW Made from 4140 steel Black Nitride finish 8-32 x 3/8" Gas Adjustment screw Two 1/4-20 x 3/16" Set Screws 1 Roll Pin Made in the U.S.A. Product Description Designed to fit barrels with a .750 diameter, this high-quality piece helps to improve the performance of your firearm. It's made from durable materials and easy to install, making it a must-have for any AR owner. Plus, its low-profile design won't add unnecessary weight or bulk to your rifle.