VEVOR Inline Duct Fan, 4-Inch 200 CFM with Variable Speed Controller, Quiet AC-Motor Ventilation Exhaust Fan for Cooling Booster, Grow Tents, Hydroponics

Works as advertised. However, there is a small issue when blowing air through an filter which causes more resistance. Doing this on lowest speed setting will blow out the speed controller and thereby stop the fan from running at all. Not an issue for me as I was just running some tests.

Ni un ruido casi perfecto

Good item, works very well. It came quicker than stated which was good. Seller was very helpful, they kept me up to date all the time and were very friendly, i highly recommend.

es bueno solo que si requieren para extraer de un lugar amplio este no lo recomiendo ya que es pequeño, pero para algo pequeño funciona.

Excellent so far after a week of use. I installed this to provide active fresh makeup air for my range vent exhaust. Inline with a damper that feeds directly into my HVAC air return, this fan and easily adjusted speed controller has allowed me to balance interior pressure with the highest setting setting my middling 375cfm hood fan can provide. In testing at full speed, it was able to pressurize the house by about the same amount my hood was depressurizing. So for the money, these fans definitely seem to meet their rated airflow spec and really do move a LOT of air. Mounting it on a shelf was super easy. Using rigid ducting was an easy fit, crimped or uncrimped. Just pay attention to how the motor housing assembly can fall apart after removing it from the bracket for mounting. It's not a big deal and easy to figure out how it goes back together, but the interior venturi bezel is not fixed in place when the motor section is removed and may fall to the floor if you aren't careful. It's also reasonably quiet. I can hear a slight humming sound through the wall into the adjoining kitchen when it is on, but that is likely because I did not use the isolation feet though, so that is on me. In the garage where it's mounted, I can scarcely hear it at all over the central HVAC fan running. Obviously, wiring requirements may vary, but having a plug has been a convenient extra (with a smart outlet currently controlling it) until I can get it hardwired into a proper makeup air control from my vent hood.