The Timber Creek Outdoors Low Profile Gas Block Is Precision machined from steel with a black phosphate finish. It will fit under most free float handguards on the market. The dual set screws securely attaches to AR barrels with a .750" diameter gas seat. Upgrade your modern sporting rifle with this performance part.Specifications and Features:Machined Durable SteelManganese Phosphate Finish.750" DiameterAesthetic CutsBlack