Angstadt upper receiver pistol 9mm 6" m-lok black FEATURES:Caliber: 9mm NATOTwist: 1:10"Barrel Length: 6"A2 style flash hiderMil-spec charging handleCompatible with both GLOCK and COLT style 9mm dedicated lower receiversWeight: 2.6 lbs Other Features: Complete upper with bcg, works with any 9mm ar lower, barrel threaded 12x36 tpi, 5.5" m-lok handguard, works with both glock and colt style 9mm dedicated lowers, all atf rules apply, for use on pistols only