The Posture Perfect Sit Upon allows you to sit for hours with perfect posture while quilting, sewing, driving and more. Softly inflated flexible disc prevents fatigue and reduces pressure on the tailbone. Helps relieve lower back pain, strengthens core muscles and improves posture. Nubby texture allows cooling air flow and promotes improved blood circulation. Durable purple rubberized material remains soft and pliable. One size fits all. Comes with an air pump to inflate the sit upon as needed. Treat your self today!