Turn over the Quad Hearts Liquid Timer and watch the liquids drop down into the lower portion while turning the heart wheels. It takes approximately two to three minutes (depending on room temperature) to completely empty into the lower portion. Great prop to keep on a science table for the children to tip, turn and watch as the liquid turns the wheel. Heart Quad timer can also be used for teacher or child stress/relaxation, quiet time toy, refocusing prop, anxiety prop, or a timer. The Quad Hearts Timer is 5 1/2" tall.