... .Key Type Air Shaft 2.Specification: 1.5" 2" 3" 4" 4.5" 6" 8" 3.Length: Max to 3.5m ... 4.Material: No.45 steel| Aluminum Key type air ... aluminum alloy, shaft body plating chromium, accurate assembly, convenient to use and long operating life. When using, ... barrel, when unloading, press on deflated mouth to deflated, then nitrogen-treated barrel can be unloaded ...