6" Upgrade Kit for FM-9 9mm AR-15/M16 Belt-Fed Upper Receiver

6" Upgrade Kit for Freedom Ordnance FM-9 9mm AR-15/M16 Belt-Fed Upper Receiver This kit upgrades your Freedom Ordnance unit to use the 16″ barrel. (You must own a Freedom Ordance FM-9 9mm Upper to use this kit. Uppers can be purchased below.) Kit includes: One 6″ barrel One 4″ quad rail One 9″ 7/64 T handle hex wrench Specifications 9mm 6″ barrel is made from 4150 chromoly steel with a QPQ nitride finish 4″ quad rail is black anodized billet aluminum with picatinny rail system Manufactured by Freedom Ordnance