Premium MaterialSomersault Auxiliary Ball is made of premium PVC material and features multi threads design for uniform pressure release and pressure resistance. Automatic ReturnSomersault Assist Ball is designed with an automatic return feature that creates a sense of weightlessness when it bounces, making it great for backflip training. Versatile UseSomersault Ball is not only great for backflip training but also ideal for waist and abdominal training, yoga assistance, stretching, sensory integration training, and more. Adjustable StrapsSports Ball is with 250kg heavy duty, nonslip, also equipped with detachable and adjustable shoulder straps, suitable for both kids and adults. Package IncludesThere 1 Yoga Ball in package, not easy to break, reliable, durable and lightweight, great for fitness and workout accessories. Specification: Material: PVC Size Chart: 55cm/21.65inch Package Includes: 1 Yoga Ball 1 Inflator Pump 1 Pair of Straps 1 Air Plug 1 Air Pull Note: Please allow slightly errors due to manual measurement and different monitors.