Seat Cushion, 15-3/4 quot;x10 quot;x2-7/8 quot;, Black 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 cut-away contours slope away from pressure points at the tailbone. Wedge shape helps promote proper seating posture.