For the most reliable optics and mounting systems choose Weaver. The Weaver name is synonymous with high-quality and affordable shooting sports products. Nobody makes bases to fit as many guns as Weaver. Yet each base is machined to tight tolerances for a custom fit. They're designed to fight the effects of recoil with a square cut notch that precisely mates to the sturdy cross bolt in every Weaver Detachable Ring. Custom hardened fastening screws come with every Weaver base.Specifications and Features:Manufacturer Number: 48015Weaver Detachable Top Mount Base Marlin Savage Winchester 75 BlackMachined to tight tolerances for a custom fitFor detachable and adjustable ringsAluminum bases offer maximum strength for rings to hold tightNo. 15 mountColor: Black Note: 2 of these are required to mount a scope