Lastest variant of the JG HK416, sporting a longer barrel and butt stock is now in stock at RSOV.com. This release from Jin Gong (aka Golden Bow, JG) is modeled after the Heckler and Koch HK416. Basically, the HK416 is an improvement over the famous American M4/ M16 by using a proprietary gas system derived from the HK G36, replacing the direct impingement gas system used by the standard M4/M16. This results in a more reliable and less maintenance by the reduction in heat and fouling of the bolt and also creating less stress for important components. 

It was initially made as a drop in kit for existing AR based weapons, though eventually HK mad it a standalone. It has a free float forend equipped all four sides with MIL-STD Picatinny rails. It uses HK based front and rear sights, is compatible with STANAG M4/M16 based magazines, as well as most parts made for the AR variants.