I needed to replace a dimmer of the same size/shape because I switched to LEDs and the old dimmer caused flickering with the LEDs. I tried different LEDs; they all flickered with the old dimmer. I changed to this dimmer and no flickering at all with several different brand LEDs I tried. And the product is exactly the same size/shape and the installation was smooth, except for some difficulty removing the cover plate to access the screws. I was able to re-use the chrome cover plate and knob as well.I only give it 4 stars because I would like the lowest setting to be even lower. When I tried brighter LEDs, I couldn't dim them enough for comfortable mood/background lighting. So I have to compromise and use LEDs that aren't quite so bright.These dimmer switches are the exactly the same as the factory dimmers installed in my 2005 Fleetwood Providence motorhome, with the exception that these dimmers are LED compatible, unlike my OE dimmers. I am converting all of my RV’s lighting over to LED, so I was happy to find the same dimmer, which fits in the same hole without any modification to my walls. While they are more expensive than what I had hoped for, they handle LED’s very well. My OE dimmers all have a brushed nickle plate/cover and knob, which I was able to easily transfer over to these dimmers. I ended up adding a extra set of LED lights under the edges of my galley counter tops, so I ordered an extra dimmer. I contacted the manufacturer, ITC, and they supplied me with an additional brushed nickle plate and knob for $12 plus shipping.Changed out bad dimmer switchThis is the same switch I have with my other lights. The old switch went bad, so I bought this replacement. Had it a few weeks and started to buzz. It got VERY hot to the touch so I turned it off. Then it turned the lights on BY ITSELF WHILE OFF! I quickly uninstalled, saw the box and cover plate melting! I cut the wires. It must have melted so much inside that the contacts closed. I easily returned it. But, I can't find this switch anywhere else so I'm thinking I have to buy from here again and trust that it was just a faulty switch. 4 stars.UPDATE: Well, now the replacement switch has gone bad. Last night the lights would not go on unless the switch was all the way on, and even then we're dimmed very low. Tonight, it doesn't work at all. I have other original switches in my 5th wheel that are still working. This is a 2008! 3 stars.Dims our incandescent and LED lights in our new RV wonderfully. Takes some trial and error in wiring the RV to figure out which is "in" and which is "out" power in the existing RV wires, but that's the RV problem not this dimmer. Dimmer is polarity sensitive and says so right on the instructions and the dimmer wiring. Just kept switching the RV wires until it worked. Then it worked perfectly. Have replaced 3 on/off switches now in the RV with these dimmers. 3 more to go!The switch worked good as a replacement switch for lights in our camper, but did have a humming sound when turned on.I haven't quite figured out what is going on with this dimmer, but it only seems to operate between 50 and 100 percent. I had hoped to be able to create some mood lighting, but it doesn't turn the lights down nearly far enough, so I am a bit disappointed. The LED lights it is controlling total way less than 100w, so perhaps that is a limitation, can't say for sure. Other than the range limitation, it seems to be a reasonable quality product.As others indicated this product does not come with installation instructions. You have 4 wires that you need to figure out what to connect to. Also, I ordered the black switch with chrome screws to attach. Unless you order the cover place that is optional which you are not told, you will have a black plate with 2 silver screws showing.Exact replacement in the camper, works perfectly.Work great, like originals