Being a retired teacher, I was excited to buy this for my granddaughter because she was very interested in how the body works. We had fun going through the book and reading the information as we extracted the parts. We did have trouble opening the skull, but it did open. The frustrating part came when we tried following the directions to put it back together. We still haven't been able to get the hips to stay together. The sticky organs are fun, except when you are trying to put them back in order. Their stickiness becomes a con. After the excitement of operating the first time, we've only used it one more time because it's too hard to reassemble it!  Also, I think the hips are defective. The "pro" of this toy is the book and information for the body parts as the child operates.