The outline border adopt advanced automatic process, more accuracy, material adopt zinc coat and zinc plate 2. The aluminum metal alloy of the high strength hub, adopt aviation aluminum magnesium metal alloy, light weight, high strength, good tensile 3. Strap adjust automatically, no need manual adjustment during lifetime 4. Shutter adopt special push-pull, open- close device, ensure shutter totally open and close, windproof, rainproof and dustproof 5. Newly punch forming fan blade, reasonable angle and reach the max. Air flow, mini. Noise 6. Double bracing (E style) belt transporter, Europe industry motor standard 7. Safety net easily tear down 8. Strictly quality test process: Noise test, vibration test, concentric performance test, fan blade turning speed test, input air test and vehicle efficiency test.