Watch these drops roll and bounce as they make their way around and around this Spiral Timer. This 5 inch liquid Spiral Timer will make you just want to watch it over and over again. The little oil droplets roll down the spiral "staircase" and it continues for about 5 minutes! Once all the droplets reach the bottom just flip it over and you'll start the drops rolling and dropping again! This Spiral Timer makes a fun way to study the scientific principles of liquid density and hydro-dynamics and it's just plain relaxing to watch!