Product Name: Boxing Speed Ball，boxing reflex bagBall color: redMaterial: Just bold/ABS/solid inner linerAdjustable height: 135-155 cmFunction: physical fitness, puzzle and decompressionUse environment: all groundStability: The base can be filled with water and sand◆ Features- Easy to Set Up & Store- Reasonable Rebound Speed with Steel Spring- Sturdy Base- Low Noise- Durable & Easy Cleaning Punching BallWARM TIPS● InstallationYou could fill in the base with sand by a funnel.● OperationBefore working out with a reflex bag, put some hand wraps and gloves on. It’s important that your knuckles are protected at all times.● MaintainanceWipe it down frequently to keep moisture off the material so that it will last longer.