While this book is filled with awesome facts about the human body the most amazing part is the human body you get to build! My son puts it together over and over. He's seven and it's almost as big as he is. The pieces pivot and fit together nicely. The organs, and brain all come out and are part of the puzzle. It's just so super cool and fun! I have just as much fun as he does. Of course the book part is wonderful too, full of great facts and info. This has sparked an interest in how the body works that I love and am happy to feed. You have to check this out. It's worth every penny!