From about the age of 5 my son became very interested in factual books. This is a really good book and the lift-the-flap format works really well with this subject - helping to picture what is inside the body. At first I was reluctant to order it because it is only 16 pages long - however, there is so much detail and information it is a really good buy - always something else to look at and discuss with my son. I agree with the other reviewer that there is a lot here to make it a useful & informative book for primary school level too. Well made solid book with sturdy flaps. I think I will purchase further books from this `See Inside' series.