If you're looking for a more robust mounting method for your gas block... look no further. Pinning your gas block, in addition to the use of set screws, gives the user the extra piece of mind that your gas block won't shift or loosen while firing. Faxon took some of Faxon's most popular barrel models and took the biggest headache out of pinning your gas block by pre-notching the gas block journal and drilling corresponding holes in the included low profile gas block. Each Pinned Gas Block Barrel comes with the pin, as well as a gas block. Gas blocks are hand-tightened to the barrel for shipping. Faxon Firearms barrels are the pinnacle of value. Manufactured in- Mfg: Faxon Firearms