The Vltor Low-Profile Set Screw Gas Block in Stainless (GB-2S-S) is small enough to fit inside most rail systems that are currently being offered for the AR15/M16/M4 weapon system. The Vltor Low-Profile Gas Block covers one-inch of the barrel's surface and is made to the tightest tolerance. These gas blocks are offered in 17-4PH stainless steel, in your choice of a matte Black Oxide or Silver bare finish.
Installation and legal note: The installation of the Vltor Low-Profile Gas Block should be performed by a qualified gunsmith and/or certified armorer.