MI AK Alpha Series Railed Top Cover is ONLY for use with MI AK Alpha Series handguards (MI-AK-ALPHA6, MI-AK-ALPHA10.0). *Not compatible with other Midwest Industries generations or other manufacturers products. Features patented components provide accurate return to zero solution for existing AK firearms. Adjustable locking block to fit on most AK firearms, recoil spring button made specifically for AK Alpha Series top cover. Rigid lockup ensures dust and dirt does not enter firearm, uses two aluminum and two steel stability struts for a solid lock up, maintains factory rear sight with lower 1/3 cowitness sight picture. No permanent modifications needed for installation on MI AK Alpha Series handguard or firearm allowing user to put firearm back to stock form if desired.