Check out
www.solatube.com which should answer all your questions.
There are other makers of "solar tubes", but I believe "Solatube" was the original. We had three installed in the home we built up north in 1998. At the time they were a new concept and my builder thought I was crazy. By the time the house was done he didn't think I was so crazy
The Solar Guys, whom Sidney referred to, install the Solatube brand. We had them install one in our previous Duval home and may get one for our new Bonita home.
If you want some natural light in your home Solatubes are the way to go.