Gas Blowback Airsoft (yes, that's the name of the YouTube channel), give their take on the GHK SIG 553 GBB. The GHK-553 is a realistic Airsoft replica of the SIG SG 553, featuring metal alloy construction for the receiver, rails, internals, and outer barrel, with a polymer magazine, stock, hand guard, and pistol grip. It has a 3-round burst fire mode, a gas blowback system for realistic recoil, and a quad RIS front handguard for adding accessories.