POF’s unique Adjustable Gas Block/Gas Tube System offers easy regulation of your rifle’s gas system to achieve optimum operating efficiency. They are available in different sizes according to your rifle’s barrel length; Carbine length / MID length & Rifle length. Nine different tuning positions allow for complete control over variables such as recoil, suppressor use and ammunition differences. Control the rate of fire, gas flow, and ultimately the reliability of your rifle. Adjusting the gas system is easy – the front of the gas block has a dial that accepts a flat screwdriver, 3/32” hex wrench, or the adjusting tool included in the kit. The system features a straight gas tube to eliminate the heat buildup that exists at the bent portion of a standard gas tube. This feature is extremely important for select-fire and/or suppressed rifles which are subject to very high heat levels. By reducing the built up heat, reliability and durability are improved. The Gas Blocks and Regulators are machined from 4140 Chrome Moly steel – Nitride Heat Treated for the utmost durability. The Gas Tubes are made from 304 Stainless Steel. The system mounts on .750” diameter barrels by means of taper pins or set screw, and as existing gas block or sight base removal is required, installation by the WW factory or a skilled armorer/gunsmith is recommended. These Gas Blocks are intended for use with free-floating handguards only. Photo shows complete package as well as component parts in various lengths and adjusting tool. Made in USA by POF (Patriot Ordnance Factory). How to Install