Finish your rifle build with this high-quality Aero Precision M4E1 Threaded 14.5in 5.56 Mid-Length w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider. Aero Precision designed these AR15 Upper Receivers with QD sling sockets at the 3, 6 and 9 o'clock positions for simple sling attachment that creates a more comfortable carrying experience. This Aero Precision M4E1 Threaded 5.56 NATO w/ ATLAS S-ONE Handguard Complete Upper Receiver is outfitted with both a front and rear Picatinny rail for that attachment of scopes, lasers and other accessories. Also, the center of the top rail has been removed to reduce the weight. Greatly improve your weapon build by installing this Aero Precision M4E1 Threaded 14.5in 5.56 Mid-Length w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider. Specifications for Aero Precision M4E1 Threaded 14.5in 5.56 Mid-Length w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider: Manufacturer: Aero Precision Cartridge: 5.56x45mm NATO Barrel Length: 14.5 in Barrel Profile: M4 Gas System Length: Mid Length Barrel Twist Rate: 1-7 Muzzle Device: A2 Flash Hider Gun Model: AR-15 Condition: New Fabric/Material: 4150 CrMoV Gas Block Journal Size-Diameter: .750 in Handguard Length: 12 in Handguard Style: Hybrid Rail Gun Rail: M-LOK Gun Make: AR Platform Weight: 50 oz Magazine Included: No Country of Origin: USA Features of Aero Precision M4E1 Threaded 14.5in 5.56 Mid-Length w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider New enhanced forging that gives the upper receiver a "billet look" New picatinny profile that blends seamlessly with our Enhanced Series Handguards M4 Feedramps .250 takedown pin holes Laser engraved T-marks Includes port door and forward assist installed Front and rear picatinny rail Eliminated center of top rail for weight reduction Indexing grooves in 12:00 position for positive grip control Quick disconnect sling socket at the 3, 6 and 9 o'clock positions Compatible with low profile gas blocks Compatible with mil-spec AR15 upper receivers and barrels 4150 CrMoV, QPQ, gas port drilled .0785 gas port M4 Feed Ramp Extension HP and MPI tested Standard A2 flash hider Package Contents: Aero Precision M4E1 Threaded 14.5in 5.56 Mid-Length w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider 5.56 CMV Barrel Low Profile Gas Block Mid-Length Gas Tube