Low Profile Design Made of High Strength Steel Magnesium Phosphate Finish Fits .750 Diameter Barrels Fully Adjustable PRIs Low Profile Adjustable Gas block is a perfect option for those looking to configure their rifle for absolute best performance with their chosen ammunition. Adjustable gas blocks are a huge improvement when it comes for suppressor use or irregularly demanding conditions. The PRI adjustable gas block gives all the control to the user without the massive footprint that some adjustable gas blocks use. Made from 1141 high strength steel with a magnesium phosphate finish, this gas block is a perfect fit for .750 diameter barrels.