Great whitener, LED light inconsequential
Very effective and gets the job done. Some visible results with first few uses. I'm not confident about whether the blue LED light makes any appreciable improvement on top of the whitening gel. The LED light was also cumbersome because it made it difficult to control saliva (swallowing or spitting).  I still rate very highly because I was only looking for a good powerful whitener, which it is, though I'm ambivalent using the LED light.
Rating: 4 stars