Aero Precision APAR308233M25: This Complete Upper includes Aero Precision\'s Gen 2 Enhanced Handguard! Key features include the addition of quick disconnect sling sockets, enhanced milling design for grip and visual appeal and a new profile for the picatinny top rail. This complete upper does not include a BCG or Charging Handle. Includes: M5E1 Assembled Upper Receiver 16.6\" Gen 2 M-LOK Enhanced M-LOK Handguard 18\" .308 CMV Barrel Low Profile Gas Block and Rifle Length Gas Tube Product comes assembled M5E1 Upper Features: Forged from 7075 T6 aluminum Precision machined to our specs M4 feedramps Laser engraved T-marks .2795" takedown pin holes Accepts standard AR .308 components Comes with forward assist and port door installed Handguard mounting platform is forged into the receiver Gen 2 Enhanced Handguard Features: 1pc free float design Built in anti-rotation tabs Scalloped rails Continuous top rail 1.78\" inside diameter fits most muzzle devices and 1.5\" suppressors Compatible with low profile gas blocks Gen 2 Feature - Quick disconnect sling socket at the 3, 6 and 9 o\'clock positions Gen 2 Feature - Additional milling along flats to aid with gripping and add visual appeal Gen 2 Feature - New profile for the continuous picatinny top rail 18\" .308 CMV Barrel Features: Twist: 1 in 10 Threading: 5/8 x 24 Material: 4150 Chrome Moly Vanadium Steel Finish: QPQ corrosion resistant finish both inside and out Gas Block Journal: .750 Gast Port: .089 Gas System Length: Rifle Weight: 56.64oz DPMS Barrel Extension HP and MPI Tested