- Ages 6+
- Size: 90 x 18 x 9 mm
- Colours may vary and are picked at random

A rattleback is a semi-ellipsoidal top which will rotate on its axis in a preferred direction. If spun in the opposite direction, it becomes unstable, "rattles" to a stop and reverses its spin to the preferred direction.

This science wonder is a great tool for endless fun, and the origin of design can be found dating back to Celtic and Egyptian sites in the 19th century. Made from plastic, this science curiosity has a curved side which creates this physics phenomenon.