1) 0-100% speed controlling: setting whatever speed you want
2) Cold-rolled steel housing; jet-engine design double impellers
3) EC(Electronically Commutated) Fan Motor: extremely energy efficient running at 1/2 the power of comparable fans
4) Locked Motor Protection [ Auto- Restart ] ; Soft- Start Motor; Over-Voltage Lockout Protection
5) IPX4 protection class, waterproof and dustproof more effective
6) Double Heavy Duty NMB Ball Bearing, not easy fever, life expectancy up to 85,000 hours