Euler's Disk

Euler's Disk is a chrome plated steel disk that is 1/2" thick and 3 inches wide. One edge is carefully machined to a smooth radius. Nine pieces of magnetized holographic foil make a variety of brilliant surface designs. A concave mirror base provides a setting for the disk to spin on like a coin... a coin that doesn't seem like it will ever stop. For ages 8 and up.