Feature:1. Made of high quality PVC material, lightweight and durable, no easy to deform.2. Bottom chamber is for water or sand to increase weight to keep it stand stable on the ground, more stable and reliable.3. Upper chamber is for inflating air to avoid scratching the skin of your limbs, soft and elastic.4. Resilient backbone for better stability, bounce back up immediately without falling over.5. Great accessory for improving coordination and flexibility, burning calories and relieve pressure, suitable for kids, teens and adults.Specification:Features:Made of high quality PVC material, lightweight and , no easy to deform. Bottom chamber is for water or sand to increase weight to keep it stand stable on the ground, more stable and reliable. Upper chamber is for inflating air to avoid scratching the skin of your limbs, soft and elastic. Resilient backbone for better stability, bounce back up immediately without falling over. Great accessory for improving coordination and flexibility, burning calories and relieve pressure, suitable for kids, teens and adults. Specifications:Material: PVC Color: Black Length: 145cm / 155cm (optional)145cm: Length: 145cm / 4.8ft Bottom Diameter: 53cm / 20.9in Thickness: 0.25mm Weight: 0.51kg / 18oz 155cm:Length: 155cm / 5.1ft Bottom Diameter: 63cm / 24.8in Thickness: 0.3mm Weight: 0.7kg / 24.7oz Package Size: 28 * 18 * 5 cm / 11 * 7.1 * 2in Package List: 1 * Punching Bag 1 * Inflatable ToolPackage List:1 * Punching Bag 1 * Inflatable Tool