The Promag AA124 Picatinny Rail fits the Archangel OPFOR AA9130 Forend Rail in black polymer and is crafted by ProMag to match the Mosin-Nagant Precision Rifle Stocks forend with the same proprietary polymer compound. This 5-inch rail aligns parallel to the barrel in the horizontal plane to provide a stable, precise mounting surface for lasers, lights, and other accessories, while tapping into the ventilation holes on the underside of the forend for secure attachment. Its thoughtful design accommodates a rail-mounted bipod and leaves ample room for additional hardware, making it a versatile upgrade for precision shooting setups. If your Mosin rifle or carbine requires the available barrel-tensioning device, the Promag AA124 is engineered to permit tensioner adjustment with the rail installed, ensuring a robust, tensioned fit. Made in the U.S.A., this accessory carries the Archangel OPFOR trademark as a registered mark of Archangel Manufacturing Company, a division of ProMag Industries Inc., underscoring its quality and intended use for dependable field-performance.