Leupold 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.Specifications and Features: Series: Cross-Slot Base Model: BackCountry Firearm Fit: Marlin 336 Color: Matte Black Action: Short Material: 7075 T-6 Aluminum Firearm Type: Rifle Rings Included: No Style: Cross-Slot Length: 5.90" Includes: Mounting Hardware