Lorje Fitness Exercise Sport Yoga Ball Inflatable Bed Pool Air Stopper Plug Pin 10PcsIt is gym ball air stopper. Fits for most gym ball size: 55cm, 65cm , 75cm and 85cm. Features: Material: Plastic Length: 5.2cm Top diameter: 1.2cm Package: Quantity: 5 piecesFeatures of Lorje Fitness Exercise Sport Yoga Ball Inflatable Bed Pool Air Stopper Plug Pin..