Full size. L1-L5 with sacrum. Full lumbar nerve with right side sacral nerve & sciatic branch with herniated disc. 4-1/2" x 3-1/2" x 11". 5" x 6" x 1" White Base included with every Spine model. Made of durable high quality materials. 100% Satisfaction Guaranteed!!! (Model must be returned within 30 days.)