Features: ONLY for use with MI AK Alpha Series Krink handguards (MI-AK-ALPHA-BKM, MI-AK-ALPHA-BKQR) Not compatible with other Midwest Industries generations or other manufacturers' products Patented components provide accurate return to zero solution for existing AK firearms Midwest Industries recoil spring button made specifically for AK Alpha Series top cover Extremely rigid lockup ensuring dust and dirt does not enter firearm Utilizes two aluminum struts for a solid lock up Integrated rear sight allowing you choose an optic or basic setup 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 Top cover and main stability struts constructed from Hard Coat Anodized 6061 Aluminum Steel locking block made from 4140 steel Made in the USA Multiple patents pending Lifetime Warranty Compatibility Disclaimer: Made to fit on most AK Krinks such as PSA and Riley Defense