With the various rail systems currently being offered for the
AR15/M16/M4 weapon system, the Vltor Low-Profile Gas Block is small
enough to fit inside most rail systems.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
matte Black or matte Stainless finish. Uses two set screws from the
bottom to attach to barrel. Fits barrels with a diameter of 0.625
inches. Gas tube roll pin included.