This is such a neat product! I found it at Wal-Mart a few weeks back while buying pool chemicals. It came in a b to onus pack, one large light and a smaller light for under $20.00.
After several failed attempts of trying to get a picture that would show this, I went to their website to snag this picture, also here is the link if you cannot find this at your local Wal-Mart : http://www.game-group.com/retailers/products.php
These lights float in the water freely or you can attach them, either way works great.
Let me just say the two lights illuminate our pool beautifully! Outside of water they are even brighter!
They have three settings from super fast and flashing to a fade in, fade out and you turn them on and off by depressing a button on top of the lights.
It does take 3 AA and 3 AAA batteries, and I do suggest investing in rechargeable. Something I really like is after running for 60 minutes it has an automatic shut off.
There is a warning on the package for people with photosensitive epilepsy, the rapid flashing of the super bright LED lights could trigger an episode.
This is something I am glad I bought and my children really love it, they would rather swim at night now!