The BT17 - 4 inches 1913 picatinny Rail is a versatile and robust mounting solution designed to enhance your firearm's adaptability. Engineered to accommodate hole patterns with a center-to-center spacing of 2.2 inches - 3.5 inches, this rail features a flat back, making it ideal for installation on flat surfaces. Its design includes a flush cup, providing compatibility with flush cup sling swivels and sling studs, although these are not included with the rail. For secure attachment, you can utilize a standard sling stud and sling stud spacer or opt for two button head machine screws as fasteners. Please note that no hardware is included with this product. For those looking to attach this rail to the forearm of standard rifle stocks, refer to the BT1517 for guidance. Crafted to meet picatinny rail standards, the BT17 is machined from high-quality 6061-T6 aluminum, ensuring durability and reliability. It features a mil-spec type III class 2 finish, offering superior resistance to wear and corrosion. Available exclusively in a sleek black finish, this rail is a perfect addition to any firearm setup, providing both functionality and a professional appearance. Atlas 1913 rails are engineered for the attachment of Atlas Bipods to picatinny rails The 4 inches rail version is compatible with hole patterns ranging from 2.2 inches - 3.5 inches and is designed for flat surfaces To attach to the stock, a sling stud and spacer or machine screws are required