Ultra-low profile gas blocks are the ideal companion for Faxon Firearms (or any other) barrels with a standard diameter gas journal. Made from high-strength steel, all our gas blocks are a matching black luster to our barrels. For lightweight builds, the block is drilled through the middle of the profile. The gas block clamps on to the barrel using 3 allen keys on the bottom of the block. Barrel Compatibility .625″. Includes mounting 3x Screws (Allen Key interface)*Gas block does not include the gas tube roll pin.