Einstein Cube

Patented by REFO Verlag GmbH 2002.
(plastic, 2.6 inches)

Turn the 6 rings so at each of the 12 places they meet the colors match. This is a slightly simpler and more colorful version of the Turn 12 puzzle that as 24 numbers on each ring (each in the range 3 to 9, where matching is by adjacent numbers summing to 12 - see Jaap's Page). Here are the directions that came with the puzzle:

Further reading:
Jaap's Page, from: http://www.jaapsch.net/puzzles/turn12.htm
REFO DE Patent, from: www.epo.org - patent no. DE20112728