EISCO super ultimate wave form helix with wooden stand and it is not a toy. It is a scientific instrument. This looming tower of metal dwarfs the standard toy at twice the closed height (20 cm vs. the standard 10cm) and can be stretched out way longer than you would expect to amplify the impact of your demonstration. Plan on your students/friends/families/strangers not quickly forgetting the waves you form with this. If you plan on putting this down some stairs, the step height needs to be pretty tall (definitely taller than a standard staircase). Grades 9-14. For ages 14-21.