Yankee Hill Machine Company 2 Piece Railed Gas Block Assembly Features The Yankee Hill Machine 2 Piece Railed Gas Block Assembly is designed to regulate gas flow from the barrel to the operating system of an AR-15 pattern rifle a critical function for reliable semi auto cycling. Its two piece design splits the gas block into upper and lower halves that clamp around the barrel simplifying installation compared to a one piece slip-on block that must be pinned or set screwed into exact alignment. The integrated rail section on top of the block provides a mounting surface for a front sight or other low profile accessory without requiring a separate rail segment. This modular approach lets builders tailor their upper assembly to their intended use. Yankee Hill Machine has built a reputation on precision machined AR-15 components and this gas block assembly reflects that focus on fit and function. The railed design keeps the front of the upper assembly clean and consistent with Picatinny spaced accessories elsewhere on the rifle. Whether replacing a damaged factory gas block or completing a custom barrel build this assembly provides a dependable properly dimensioned component for the task. The Yankee Hill Machine 2 Piece Railed Gas Block Assembly is available for sale at GrabAGun for AR-15 builders and owners in need of a quality replacement part. Yankee Hill Machine Company 2 Piece Railed Gas Block Assembly Specifications Manufacturer: Yankee Hill Machine Company Model: 2 Piece Railed Gas Block Assembly Compatible Hosts: AR-15 Available At: GrabAGun