LWRC's IC-A5 Upper Receiver is a perfect start to a custom, high-performance AR-build. Originally designed for the U. S. Army's Individual Carbine program the IC-A5 Upper is equipped with a patented short-stroke gas piston system offering the shooter unparalleled reliability and easy maintenance in any conditions. The short-stroke gas piston system is perfectly paired with a nickel-boron coated bolt carrier for unmatched resistance to wear and corrosion while also providing permanent lubricity. This IC-A5 Upper Receiver is a Monoforge design with integrated 12" SPR style rail base and a low profile 2 position adjustable gas block allowing the shooter to compensate for running a suppressor with the added benefit of a longer modular rail system. The upper rail section on the IC-A5 Upper Receiver is an aesthetically pleasing special cutback version which allows the use of a low profile gas block and at the same time keep the full 9" modular rails available on the sides and bottom of the hand guards. Features of the IC-A5 Upper Receiver: LWRCI PROPRIETARY SHORT STROKE GAS PISTON SYSTEMLWRCI COLD HAMMER FORGED SPIRAL FLUTED NICORR-TREATED BARRELLWRCI ADJUSTABLE 2 POSITION GAS BLOCKLWRCI BIRDCAGE (A2) FLASH HIDERLWRCI SKIRMISH BACK UP IRON SIGHTSLWRCI 12" USER CONFIGURABLE RAIL SYSTEMLWRCI AMBIDEXTROUS CHARGING HANDLEH2 BUFFERCARBINE LENGTH ACTION SPRING LWRC International LWRC IC-A5 5.56mm NATO 14.7" 1:7" P& W Bbl OD Green Complete Upper Receiver ICA5U5ODG14P