Improve posture anywhere with an inflatable vinyl disc that strengthens core muscles while you sit. A bumpy, grippy bottom side prevents it from slipping in any situation, and a subtle texture on top provides a plush, sensory experience in chairs or on the floor. Includes an air pump to inflate the disc to desired thickness. Add more air for slightly more traditional seating or remove some to increase instability and work out wiggles. Vinyl construction is extremely durable and easy to clean for long-lasting use. Supports up to 220 lb. 13" dia x 1" thick; 1-1/2 lb.