Patented by M. Fritsche 1986.
(plastic, 2.5 by 3.25 by 3/8 inches)
Two rings each contain seven discs each
(six at 60 degree increments around the edge and one in the center)
and overlap by three discs (the center and two others) so that they can be turned to mix up the puzzle.
The goal is to restore the pattern of a top row of three red, a middle row of four yellow,
and a bottom row of three green,
and the numbers on the rows of the reverse side
(molded into the white plastic)
being 123, 4567, 890:
Fritsche DD Patent,
from: www.epo.org - patent no. 236263