It does what it says...I purchased this as a stocking stuffer for my 10 year old daughter who takes long showers. So far she doesn't really understand what it is doing. I wish there was a way to change the battery so that it would last longer. The instructions say that it will last about 3 or 4 months. I understand why you wouldn't want to be taking it apart to change the batteries, but still would like the option. Also...the lights are somewhat hard to watch. If you are spending your time watching the lights, you are going to take a longer shower!