Model of a human spine base. Accurate representation.Material: PVC Description: The size of this model is just the same as the realities and made of PVC plastic. It shows the following: Pelvis shapes: Long and narrow Pelvis cava: Like a funnel Aperture pelvis superior: Heart-like Sacrum: Long and narrow with great flexibility Angles of pelvis arch:70-75 degree Symphysis pubica: Long and narrow