I tried other but this actually worked on my commercial fan

Has been working well to turn on duct booster.Must be careful where you place air flow senser. I put it on plenum.

Works well, but would have preferred an option where I could wire a longer wire rather just a plug-in.

Simple to use.

Just got this today. I plugged my 18 Air King Air Circulator fan in and it really helped lower the rpm's and noise. The Air King has 3 speeds. I mounted the fan on the back patio where I relax and watch tv on my projector. However, even on the lowest speed, the Air King spins too fast and makes too much noise, which really interferes with hearing the audio without having to blast the volume. I left the Air King on the low setting and set the fan speed control to about 1/3. This provides me with a pleasant breeze with little noise. This is a great product and just what I was looking for. I hope it lasts a good long time. It's a little pricey, but it's made in USA, and does what it says, so I'm good with it.

it goes from max speed to about half...that is it!!!!!!!!! JUNK!!! JUNK!!! JUNK!!! I have already tossed it..........

Used for ceiling fan.

this easy to install dial, worked perfectly. we used it on the same brand fan. I overlooked the description when i bought the fan and discovered it did not have a speed control knob. i'm happy there was an easy fix.

Well made. (Although a bit retro in style). Using it to control speeds on a duct booster from the same company and it allows fairly fine adjustments.

used 2 of them

This speed controller does a great job slowing down the Tjernlund fan that I bought. It was plug in easy. Turns out it's seldom necessary to slow down the fan, but this controller does the job nicely when it's needed.

No installation , just plug and play. Well made, goes from (click) Off , knob rotates clockwise and progressively reduces the fan speed. Just what I was looking for, and no wiring work!

Purchased an 18 industrial shop fan (TPI U-18-TE, sealed PSC type motor) that would roar like a wind tunnel on low. I plugged it into this device, turned it down, and now the fan runs very slowly and quietly. I checked the motor temperature and it is the same with and without device.

Controls the fan speed to where I want it.