I didn't buy this for me. I am the children's Bible teacher and I wanted to teach them to learn the books of The Bible so they could find verses faster. The tabs are color coded according to the category the book falls under (i.e. Pentateuch,Historical, Wisdom, Prophets, Gospels, etc.). They are a bit difficult to put on as you only get 1 shot or will mess up your book. It seems to help the kids a bit.