Water rather than sand fills this 21 in wide bag, and that changes how it answers a punch. The load shifts inside the PVC shell, so a straight jab drives it back while a hook sends it arcing, giving practice at reading a moving target instead of a dead weight. The high-rebound body returns to position quickly and stays quiet, which matters in an apartment or a shared garage where a traditional heavy bag is too loud. Standing 28 in tall on an adjustable metal chain, the bag suits jabs, crosses, hooks and uppercuts from beginners through experienced boxers. The 39 in hose supplied makes filling and draining straightforward, and the empty bag weighs 15.5 lbs for easy storage between sessions.