Planet of Toys has a fantastic friction-powered toy for both girls and boys. Dump truck set is a fantastic, safe, inventive, and amusing friction toy for kids aged 3 and up. Just keep rolling, friction powered. One garbage truck, one trash truck car, and one tank truck automobile Simply push the dump truck forward a few times before letting go and watching it roll! It's a hit with the kids! Friction truck toys are ideal for helping children develop hand-eye coordination.