The Ergo 4822 .750 Adjustable Gas Block is designed to fit under the Ergo Modular and SuperLite Rail System as well as most other manufacturer's free float handguards. The gas block allows the user to variably fine tune their rifle's gas system down to full shutoff. The adjustable gas block retains the same height/profile as the standard Ergo low profile gas block. Melonite QPQ finish for durability and machined from 4140 chromoly steel with chamfered edges featuring a slip on fit for ease of installation and secured with two set screws. CNC machined 4140 chromoly steel Full shutoff with zero adjustment movement Nitride/Melonite QPQ finish Chamfered edge semi-press fit USA made steel and Machined in the USA Weighs 2 Ounces Fits under most free float handguards Internal Diameter 0.750 Same profile/height as the standard low-profile gas block Includes two set screws for a secure attachment Includes 10-32 Set Screw and a 4-40 Retaining Screw (Rearward facing) Accepts standard gas tube roll-pins but a roll-pin is NOT included.