Review on 2PCS Onite LED Strip Dimmer Switch With USB Female To Male Extension Cord And Rotary Dimmable Control Knob. by Brandon Carr

4 stars, because it does work. Connect it, turn the dial, and your device can go from off to barely on to full power.However -- I got it for an LED lamp that continuously cycles through a range of colors, and it turns out that in order to do that, the power has to be on max. I can have a red glow as dim as I want it, but the color change cycle won't start unless I turn up the power all the way. If I unplug it while on a different color, it comes on red again when I reconnect it, and stays that way unless I turn the power up. I realize this is my lamp's problem, not the dimmer, but since this is probably not an uncommon type of device to want to use this with, you should be warned it may not work for that.