The Costway 21 Inch Water Punching Bag is designed for both comfort and functionality, featuring a high-rebound PVC body and an adjustable metal chain that allows for customization based on your needs. Its water filling design mimics the feel of a real boxing experience, with a recommended water volume of 70%-80% for optimal use. This versatile punching bag is perfect for various types of boxers and can be utilized in the gym, office, or outdoors. Complete with all necessary accessories for easy setup, this punching bag is a fantastic addition to your workout routine.