Sit comfortably for hours while quilting, sewing, reading, driving and more. The Gypsy Quilter Sit Upon is a softly-inflated flexible disc that prevents fatigue and reduces pressure on the tailbone. It helps to relieve lower back pain, strengthens core muscles and improves posture. Its nubby texture allows cooling air flow and promotes improved blood circulation. The durable purple rubberized material remains soft and pliable. One size fits all!