From a quality point of view, this series of books is excellent with laminated pages and solid yet my son is far from a tender with its business. The quality is very good explanations, the designs are simple but well illustrate the text. For the specific case of 'Pool', explains us the principle of the pool; warm air, the cabins. It enumerates what it takes to go into the water and why. It explains why you spend in the shower and the foot bath, how the pool is cleaned. It presents the various sports in the pool, and how is a course for kids and baby swimming ... It is very rewarding for children from 3 years and much more!