Widely Used -- The 4inch inline duct fan is widely used in homes, offices, warehouses, restaurants, bars, shops, shopping malls, grow tents, greenhouses and other places where a lot of air is needed.Over-heat - The motor comes with low operating temperature and low heat generation, the built-in temperature device, the contact point is disconnected when the motor overheats, which acts as a power failure . double is safer.Large Airflow -- It is designed with high quality sleeve motor, quiet and energy efficient, with rotational speed 2800 r/min, 140 CFM large airflow.DIY Your HVAC System - You can supply fresh air with one or more fans to DIY air circulation systems depending on the size of your space.It is able to move air through carbon filters, long stretches of ducting or grow light reflectors. Exchange stale air with fresh air to keep temperature or humidity under control and cool your reflector with our blower! Safe and environmental friendly.Colour: whiteMaterial: metalVoltage: 220V 50HzInput power: 25WSpeed: 2800R / MinAir volume: 140m3/HRunning noise: 30-35dbsize: Diameter: 93 mmHeight: 78 mmPackage Contents:2 x duct fanOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.