Review title is Works...when it does [SEP] The kit includes gel and the rechargeable LED unit. I was able to use it for a few days and then the main LED unit stopped taking a charge and it will no longer turn on. I had to return it.<br /><br />When it works, it made a noticeable difference and did so without any pain or increased sensitivity. Normally my teeth are very sensitive and in the past, other whitening products hurt too much to use. This one was great in that regard...no pain at all.