Helps enhance traditional yoga and Pilates poses. Unlike medicine balls, which are designed to be thrown, the Poz-A-Ball is used in static positions to help improve alignment. It is air-filled and comfortable to use, lightweight and durable. Great for rehab or fitness enthusiasts who require lighter weights. Pliable, inflatable PVC. Ships deflated, includes straw to inflate. Improves overall body alignment in workouts. 8" diameter.