The back of the sacrum on this fully flexible model opens to expose the sacral portion of the spinal cord and associated nerve branches. Includes occipital plate, cervical, thoracic and lumbar vertebrae, sacrum, coccyx and complete pelvis. Vertebral arteries, spinal nerve branches, and a prolapsed L3 - L4 intervertebral disk are represented. Stand not included. 90 x 20 x 20 cm. Weight: 3 kg.