USAirsoft reviews the Classic Army M4 RIS EC2 AEG that can be found at Airsoft Station, the company providing the review unit. This AEG uses a nylon fibre body being a Sportline version thought it uses a tightbore 6.03mm inner barrel. Lipo ready, this has an initial muzzle velocity of 330-350fps on 0.20g BBs and quick spring change feature.