As a woman and a mother i only have third party experience of the vaguaries of the willy. I also realise that the last person a boy wants to ask about his willy is his mum. Some things are just beyond the pale. SO i found this book and what a gem it is. The Boys are 9 and nearly 11. My husband vetted it first because i thought he'd have a better idea of what would be needed in the way of an owners manual being an owner himself. He spent two nights sniggering and giggling and then said it was perfect. Especially for the older boy. We think that the younger boy may just find some of it gross but children tend to read or listen to as much as they can handle then switch off. It is written in a non medical fashion but without any silly inaccuracies that may cause problems later. It also covers related areas such as hygene, the ettiquette of early physical relations with girls, kissing and mutual respect but in a relaxed inoffensive manner that a boy can understand and remember. I'll leave it on their bookshelf so they can dip into it as and when they need.