This scope mount for Mossberg 640 is a Weaver/Picatinny style rail. Scope mount comes with all mounting hardware and fits Mossberg 640 and Marlin Model 60 Rifles with scope mount pre-drilled holes on top of rifle receiver the holes usually have factory installed screw simply remove them and install the scope mount. The weaver style scope mount base has 11 slots on rail to allow for flexible eye relief adjustments for tactical scope applications or red dot sights. Limited lifetime warranty
Mossberg 640 Marlin Model 60 .22 / Black
Length (Inch) 4.73
Limited Lifetime Warranty :Yes
Will also fit flat top receivers on : Marlin 9, 45, 30AS, 30AW, 336(all models), 62, 93, 336, 336C, 375, 444, 1993, 1894 Cowboy, 1895, Glenfield 30, Zane grey, Camp-9 carbine, 922M, 989, .22 auto rifle, Mossberg 640, Western field 740, 45/70 Henry.
(Note if you do not have the factory pre-drilled holes on top the receiver you will have to get it drilled and tapped.)