Introducing the Alexander Arms 6.5 Grendel Upper Kit. The kit includes: Mil-Spec flat top upper receiver (port door and forward assist installed), Our very own high quality 16" stainless, extreme lightweight barrel with a 1:8 twist, Threaded 5/8-24 TPI RH, Complete bolt carrier and 6.5 Grendel Bolt, .875 Gas Block, Mid-length Gas tube, Mil-Spec charging handle, One 10 Round Magazine. The kit does not include a barrel nut or handguard.