Leupold BackCountry cross-slot bases are meticulously crafted from the durable 7075-T6 aluminum alloy, offering a remarkable combination of lightweight construction and formidable strength. This particular BackCountry cross-slot base is specifically designed to accommodate a Nosler M21 Long Action, providing versatility for both Picatinny- and Weaver-style rings. In the realm of firearm accessories, few elements are as essential as the connection between your scope and your weapon. Leupold mounts are engineered to exemplify the sturdiness and reliability that Leupold optics are renowned for. With an extensive selection of mounting systems available, you're certain to find the ideal match for your firearm and shooting preferences. Assembled in the United States and built to withstand a lifetime of rugged use, Leupold mounts consistently deliver the dependable performance you rely on.