Unique cut-away contours slope away from pressure points at the tailbone. Wedge shape helps promote proper seating posture. Supports the lower back and spine. Softly curved upper edges reduce stress on pressure points by gradually tapering away from user. Unique center channel averts pressure on spine. Helps to maintain the spine's natural S-shaped curve. Contoured Therasoft® material keeps its shape. Nonabrasive, antistatic, washable.