This is an excellent book to introduce children to the inner workings of the human body, helping to answer all those, "Mum, why do we poo?" type of questions. It is quite robust, having thick pages, each covered in flaps which open up to reveal body parts and how they work, all tastefully drawn. The explanations are simple and straightforward eg. if it means 'poo' it says 'poo' not 'stool' or some other euphemism not understood by a child. The colours are bright and there is plenty of detail to keep a child coming back to study the pages time after time. I bought it for my three and a half year old who loves it. It is designed for children up to the age of 10 I would think, but smaller ones can enjoy it too, looking at the pictures and reading with a parent.