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.

No.63B mount

Specifications and Features:
1 piece aluminum detachable top mount base
Precision built
Square cut notch eliminates recoil
Black

Fits:
Marlin 9, 45, 30AS, 36, 62, 93, 336, 375 and 444
Marlin 1893/1894/1895, Glenfield 30, Zane Grey and Camp-9 Carbine
Marlin 922M and 989
Mossberg 640
Western Field 740