Instead of sand, the Magnetic Sand Timer is filled with black iron filings. Set the device on its stand and watch the metal grains arrange themselves into a beautiful, spiked sculpture. What's the secret? A powerful rare earth magnet is hidden in the base. Each time you turn it over, a different pattern is formed as the ferrous material is drawn into the magnetic field. Not intended as a real time-keeping device; actual times will vary. About 14 cm (5.5") tall. *Note: If the "sand" is not going through to the bottom of the timer, it may have become magnetized. Just give it a good shake, and it should start flowing freely again.