This complete upper includes our ATLAS S-ONE Handguard! The S-ONE line of handguards are designed with size and weight in mind, providing the perfect addition to your lightweight build. Our proprietary ATLAS attachment system is a durable and dependable mounting platform, maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards.INCLUDES:M5 (.308) Threaded Assembled Upper Receiver15" M-LOK ATLAS S-ONE Handguard22" 6.5 Creedmoor Fluted Stainless Steel Barrel, Rifle LengthLow Profile Gas Block and Rifle Length Gas Tube.308 A2 Birdcage Flash HiderProduct comes assembledThis complete upper does not include BCG or Charging Handle. These products may be selected as add-ons under the FINISH YOUR BUILD tabM5 ASSEMBLED UPPER RECEIVER FEATURES:Forged from 7075 T6 aluminumM4 Feedramps.2795 takedown pin holesLaser engraved T-marksDPMS High Profile (.210) Tang)Includes port door and forward assistATLAS S-ONE HANDGUARD FEATURES:Front and rear picatinny railEliminated center of top rail for weight reductionIndexing grooves in 12:00 position for positive grip controlQuick disconnect sling socket at the 3, 6 and 9 o'clock positionsCompatible with low profile gas blocks1.3" Inside diameter1.5" Outside diameterCompatible with mil-spec AR15 upper receivers and barrelsLearn More about our NEW ATLAS S-ONE Hanguards22" 6.5 CREEDMOOR FLUTED STAINLESS STEEL BARREL, RIFLE LENGTH FEATURES:6.5 Creedmoor 22" Barrel, 1/8 twist, 416R Stainless Steel, gas port drilled.936 gas block journalRifle length gas systemM4 Feed Ramp ExtensionHP and MPI testedStandard .308 A2 flash hiderSpecifications:Made In America? YesFFL SOT Shipping Required NoPlatform M5Series ATLASCaliber 6.5 CreedmoorBarrel Length 22"