These skeletons have it all!.Anatomical Model, Prem Flex Skltn w/Sacral Mount Our Flexible Series Skeletons incorporate our detachable 4-part skull with individual extractable/reinsertable teeth, flexible spinal column, resilient spinal cord with medulla, paired spinal nerve roots, cervical vertebral arteries, herniated lumbar disc between L4 and L5, detachable sacral flap which exposes the branching of the cauda equina, and detachable upper and lower extremities.