The
is a toy that propels a plastic wheel along both sides of a metal track with magnets built into the wheel. There have been many copies, but the first was: "Whee-lo - The Magnetic Walking Wheel" introduced in 1953 by Maggie Magnetic Inc. of New York. In 1957, the Whee-lo sells for 79 cents and comes with 6 "Whee-let" colorful cardboard wheel attachments that you had to ever so carefully cut off the side of the box. A favorite was the red and white spiral shape.
By tilting the track up and down, the wheel rolls the length of the track, top and bottom, and then again but on the opposite side of the wire. In this way, the wheel always keeps in contact with the track, and can be continually propelled on its cyclical course. With proper timing, the wheel can be brought to a great speed.