The Punch & Play Punching Bag for Kids lets your little ones train like the pros while having fun. The built-in spring rebound action is great for improving hand/eye coordination and overall fitness. Blow molded base can be weighted with water or sand. Inflatible punching bag attaches to the top of a spring loaded steel shaft. Height of punching bag can be easily adjusted depending on childs height. Pump and all other assembly tools included.. Base fills with 15lbs of sand or water for maximum stability. Great for active kids ages 5+