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:- Style : Weaver- Finish : Gloss BlackUse as Front base on:- Marlin: 39A, 39D, Century Octagon barrel- Remington: 12C Octagon barrel- Savage: 25 Octagon barrel- Stevens: 27 Octagon barrelUse as Rear base on:- Stevens: 27 Octagon barrel