This model represents the 36th week of pregnancy originating from a study of pregnant Japanese women. The model permits students and practitioners the ability to practice the ECV technique. Glycerin is used for simulated amniotic fluid that is delivered into the amniotic sac. The simulated amniotic fluid can be changed, and its volume adjusted for various cases. Koken models are made from a special silicone rubber that feels very much like human skin that provides the trainee with a remarkably realistic experience. This life-sized model can also be used for external pelvic measurement and breast care. The shape of amniotic sac complies to the shape of the pelvis to help make training more realistic. The head, hands and legs of fetus are more rigid than other parts of the amniotic sac, and the backbone is structured along the back of the fetus, making it easier to feel.