Mana of 18-BASE does what she says to be fast review of the Double Eagle/EMG Noveske N4 DEVGRU GBB. Available at retailers in East Asia, this is said to utilise the Tokyo Marui MWS Z-System which looks like it is getting to be the standard for AR-style gas blowbacks. This GBB rifle is made of Metal, Aluminum Alloy, and Fibre Polymer.