Army Armaments - 5.1 Hi-Capa Costa Comp R501 with Threaded Barrel mk22 it means that this AEG

it means that this AEG is site friendly both indoors and outdoors

CO2 Powered - Green Gas ready

The gas is stored in a removable gas cartridge stored in the stock of the gun

for its rock solid metal body and VFC's own take on the Magpul ACR stock

or other accessory you'd want to put up there

Army Armaments - 5.1 Hi-Capa Costa Comp R501 with Threaded Barrel mk22 it means that this AEGArmy Custom 5. 1 Hi Capa with Costa Compensator with Thread Adapter (Full Metal Black R501) Get your Chris Costa on with this Army 5. 1 Hi Capa with Costa Compensator Main features: Full Metal Construction 4 inch island type barrel with compensator Realistic Blowback System Double Stack Magazine Sealed New Generation Magazine Valves Fiber Optic Front Sight Reinforced Cold Resistant Polymer Nozzle Compatible with CO2 Green gas powered magazines