Good solid punching bag. Most "youth" bags are junk at best but this one exceeds expectations. This brand was recommended to me as Wavemaster bags are in use at the local MMA training facility. Bag is adjustable for height to allow for various sized kids. The bag itself is basically Styrofoam blocks wrapped in a nylon material bag. We'll see how well it holds up over time but right now it seems to be ok. Using boxing gloves is recommended to protect the knuckles. It can be filled with either water or sand. Water is easier, but sand is much heavier by volume. The fill spout is at the top under the pad. It will take 200lbs of sand. Make sure you get playground sand as it has fewer rocks so it is easier to pour through a funnel. Putting it on a rubber mat is a good idea to keep it from sliding on carpet or scratching wood floors.