Aero Precision APAR308554M69: This Complete Upper includes our 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 BCG or Charging Handle. Includes: M5E1 Enhanced Assembled Upper Receiver 15\" Enhanced M-LOK Handguard 18\" .308 Fluted Stainless Steel Barrel, Rifle Length Low Profile Gas Block and Rifle Length Gas Tube .308 A2 Birdcage Flash Hider Product comes assembled M5E1 Upper Features: Forged from 7075 T6 aluminum Precision machined to our specs M4 feedramps Laser engraved T-marks (Anodized only) .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: Added quick disconnect sling socket at the 3, 6 and 9 o\'clock positions Milled additional surfaces along flats to aid with gripping and add visual appeal New profile of the Picatinny Top Rail 1pc free float design Rail is Machined from 6061-T6 Aluminum 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 18\" .308 Fluted Stainless Steel Barrel, Rifle Length Features: .308 Winchester 18\" Barrel, 1/10 twist, 416R Stainless Steel, gas port drilled .750 gas block journal Rifle length gas system M4 Feed Ramp Extension HP and MPI tested Standard .308 A2 flash hider