The R-ONE handguards are designed with size and weight in mind, while still providing plenty of real-estate to accommodate any attachment needs the end user may have. Aero’s 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 Assembled Upper Receiver ATLAS R-ONE Handguard of choice 16" .308 CMV Barrel, Mid-Length Low Profile Gas Block and Mid-Length Gas Tube Product comes assembled This complete upper does not include a BCG or Charging Handle. M5 ASSEMBLED UPPER FEATURES: Forged from 7075 T6 aluminum M4 Feedramps .2795 takedown pin holes Laser engraved T-marks (Anodized Only) DPMS High Profile (.210) Tang) Includes port door and forward assist ATLAS R-ONE HANDGUARD FEATURES: Full top picatinny rail for optional attachments Quick disconnect sling socket at the 3, 6 and 9 o'clock positions Compatible with low profile gas blocks 1.5" Inside diameter 1.75" Outside diameter Compatible with AR-308 Upper Recievers with a thread pitch of 1-7/16 x 16 along with a DPMS High Profile (.210) Tang Rail 16" .308 CMV BARREL FEATURES: Twist: 1 in 10 Threading: 5/8 x 24 Material: 4150 Chrome Moly Vanadium Finish: QPQ Corrosion Resistant Gas Block Journal: .750 Gas System Length: Mid-Length Weight: 36 oz DPMS Barrel Extension HP and MPI Tested