Crafted from durable 7075-T6 aluminum alloy, Leupold BackCountry cross-slot bases are the epitome of lightweight yet robust mounts. In this iteration, the BackCountry cross-slot base is meticulously designed to fit a Nosler M21 Long Action, accommodating both Picatinny- and Weaver-style rings. In the world of firearm accessories, few components are as crucial as the connection between your scope and weapon. This principle is upheld through mounts that embody the sturdiness and reliability synonymous with Leupold optics. With a wide range of mounting systems to choose from, you're certain to find the perfect match for your firearm and shooting preferences. Assembled in the United States and built to withstand a lifetime of rugged use, Leupold mounts stand strong, consistently delivering the performance you rely on.