The two interchangeable heads, one full term, the other premature, are fastened to a flexible shaft to allow passage, in different positions, through the pelvic outlet. Both fetal heads contain skulls with palpable cranial sutures and anterior and posterior fontanels. The models can also be used in demonstrating forceps and vacuum assisted deliveries. Size: 16″ x 16″ x 13″. Three-year warranty.