Children can pour sand or water through these colorful gears and learn the basic physics of gravity and volume. This is great for bringing along on beach trips. The funnel at the top is bright yellow and feeds into a spinning, turtle-shaped gear. Underneath the turtle is a seesaw with two pockets. Then, pinwheels beneath the seesaw turn as water or sand comes down. This toy is easy to clean, colorful, and a fun way to spend a summer day.