Hong Kong-based airsoft retailer go over the features of the SIG Air ProForce MCX Virtus AEG that they have in stock. Made by VFC for SIG Air, this features the Avalon AEG gearbox,quick change spring system, built-in MOSFET and ambidextrous operation. It can accept standard M4 AEG magazines, which usually means Marui-compatible standard M4 AEG magazines.