Dark mode is

Product Unavailable

Unfortunately, the following product is currently unavailable through Rainier Arms.

Aero Precision M4E1 Upper Receiver and 12" M-LOK Gen 2 Handguard Combo - Anodized Black

AR-15 Partial Upper Receiver


The M4E1 Enhanced Upper Receiver and Handguard Combo! Their State-of-the-art Enhanced Upper Receiver combines the handguard mounting platform with the upper itself, condensing the parts needed to mount a free-floated handguard to a mere 8 screws. This Upper Receiver Handguard Combo now includes their 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.

Enhanced Upper Receiver Features:

  • M4 Feedramps
  • .250 takedown pin holes
  • Lazer engraved T-marks
  • Comes assembled, with dust cover and forward assist installed
  • Machined from 7075-T6 forged aluminum

Gen 2 Enhanced Handguard Features:

  • 1pc free float design
  • Built in anti-rotation tabs
  • Scalloped rails
  • Continuous top rail
  • 1.72" 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


  • AR15 M4E1 Enhanced Upper Receiver
  • Enhanced Handguard of choice
  • Handguard mounting screws


  • Made In America Yes
  • Platform AR15
  • Weight(s) M-LOK: 12" - 19.84 oz 
More Information
Product Type AR-15 Partial Upper Receiver
Manufacturer Aero Precision
Color Black
Rail Length 12"
Mount M-LOK
Google Customer Reviews Google Customer Reviews