'Gynaeplaque' model, United States, 1925-1935. Medical professionals were taught how to insert a cervical cap using this model. The model is spongy rubber in a black case which opens to show the female reproductive organs. A cervical cap is a contraceptive inserted before sex. It sits over the cervix and blocks sperm from entering the uterus. It must be initially fitted by a physician where they can establish the shape of the cervix and the size and type of cap required.