Toysmith Euler's Disk Spin science into art You won't believe your eyes or ears Disk will spin faster and louder the longer it goes Just give it a spin and gravity does the rest A hypnotic display of light and sound Patented 3" diameter chrome-plated steel disk Creates a hypnotic display of light and sound as it rotates Includes Disk, 9" concave mirror base and 9 pieces of holographic foil Foil is magnetized