LOHOME(TM) Single Wheel Drop Liquid Motion Desk Toy Liquid Spiral Tube Timer (Green) Size: 140*85*30MM. Attractive, fun timer that illustrates the passing of time (non-specific) as the oil and water droplets twist around the tube. Filled with clear oil and bright neon colored water which repel each other due to their different densities. Turn this colorful tube upside down and watch the fat spherical droplets spiral down to the bottom - mesmerizing! This visual sensory timer is ideal for stimulating discussion on time differentiation, keeping concentration, as a