This VFC SR25 GBBR is fully licensed by Knights Armament so you could expect it to have the full authentic markings and have the closest detail to the real on. Fully constructed in metal with a Knights Armament SR25 quad rail in the front, polymer stock and pistol grip like the real one, this is a gun you shall not miss. The VFC SR25 GBB is a gas blowback system that is an enlargered version of the VFC m4/ Umarex HK416 GBB system and has its own proprietary 20 round magazine. The receiver is made from forged and CNC milled Aluminium, and hard anodized to military spec. Both the free floating quad rail and charging handle are being CNC processed from Aluminium as well. Each of the SR25 would also have flip up iron sights and unique serial numbers. The DX version differs from the normal version with a silencer that is matching serial number with the receiver, includes a gun case, bipod adaper, a bipod, a proprietary QD silencer and 3 rail covers.