The US Toys Hydro Rocket Box Set is a set of three toy rockets that are launched with the power of water. Simply fill the rockets with water, pump and watch as they blast off. These rockets really are an example of when science meets fun, and children will enjoy the ease that it takes to watch the rockets fly around. The rockets that come in this pack vary by size and color, so your toddler can pick their favorites and reuse the rocket as much as they want.