DEMO Faxon Firearms ARAK-21 16in 5.56 Complete Upper URSSB556. Faxon Firearms designed these AR15 Upper Receivers with an ambidextrous charging handle to suit both left and right-handed shooters. This Faxon Firearms ARAK-21 Aluminum Upper Receiver features a top full-length Picatinny rail along with multiple other rails that create a comprehensive M4-style quad rail upper. Upgrade your rifle build today with this Faxon Firearms ARAK-21 AR15 Upper Receiver. Specifications for Faxon Firearms AR15 Upper Receiver Groups 1: Manufacturer: Faxon Firearms Finish: Anodized Color: Black Fabric/Material: 6061-T6 Aluminum Gun Type: Rifle Gun Model: AR-15 Magazine Included: No Features of Faxon Firearms ARAK-21 Upper Receivers: Fully machined from an aircraft grade 6061-T6 aluminum billet in a one piece design that incorporates a full length picatinny rail (Mil-STD-1913) on the top and three additional rails on the muzzle end of the receiver making it a full M4 style quad rail upper. The top picatinny rail is laser engraved for optic placement. Charging handle is ambidextrous non-reciprocating foldable spring returned and is easily relocated from left to right side without tools by the operator. Model ?39? Eight (8) lug bolt design with involute profile for both right and left hand versions. The extractor is positioned at 3 o?clock. This allows for a left hand version to use the same bolt by simply removing the cam pin and rotating 180 degrees and reinstalling the cam pin. Self-contained firing pin retention system enclosed in a rectangular bolt carrier that no longer requires a cotter pin. Bolted in hardened steel rail system for the bolt carrier to ride on. This allows a metal on metal wear surface for better wear characteristics and much smoother operation. Allows a folding stock to be added as recoil system does not extend beyond the upper receiver to fully operate. Eliminates the noise and feel of the buffer tube cycling back and forth. Package Contents: Faxon Firearms ARAK-21 Upper Receivers Manual What firearm models does the manufacturer say Faxon Firearms AR15 Upper Receiver Groups 1 is compatible with? The manufacturer suggests that Faxon Firearms AR15 Upper Receiver Groups 1 is compatible with AR-15Faxon Firearms URSSB556: AARAK-21 16in 5.56 Complete Upper