Features:Stepless speed regulation professional: 0%-100% free speed regulation control.Low power and energy saving: The power is only 20W and can run continuously for 24 hours.Strong air volume: high speed 5100rpm air volume up to 275 cubic meters per hour.Durable metal shell: compressive, wear-resistant and corrosion-resistant for up to 10 years.Application: toilet/toilet/bathroom, greenhouse/laboratory/indoor planting, reading room/library/study, meeting room/reception hall/classroom, kitchen/cellar/staff room, restaurant/canteen/barbecue shop.Features: DC motor stepless speed regulation, all series of duct fans are built-in, stepless speed governor is true stepless speed regulation, does not hurt the machine, and is more durable. Zero gear and full speed gear are free.-wide voltage and stable voltage, adopt a wide voltage design voltage range of 90-260V without any unstable power supply voltage, while improving the life of the fan.Size: 4 inches/100mm.Power: 20W.Wind pressure: 330Pa.Weight: 1.0kg.Speed: 5100rlmin.Air volume: 275cmh.