LeupoldA(R) BackCountry cross-slot bases are made of 7075-T6 aluminum, making them some of our lightest and most rugged mounts yet. This BackCountry cross-slot base is designed to fit a Marlin 336 and accepts both Picatinny- and Weaver-style rings. Nothing is more crucial than the link between your scope and firearm. That&';s why our mounts are every bit as rugged and dependable as the Leupold optics they secure. And with a huge variety of mounting systems to choose from, you&';re sure to find the perfect match for your firearm and style of shooting. Made in the USA and guaranteed to hold up to a lifetime of abuse, Leupold mounts will never let you down.