Rubik's Tangle 3x3 Double Sided
Produced in 1995.
(nine 2" square plastic pieces, patterns on both sides)
Arrange 9 squares in a 3x3 array so that edges match.
Each square has on both sides the same pattern of 4 tangled ropes that has two connections on each edge.
Different sides of different squares have a different combination of the four colors
(red, green, blue, and yellow).
More confusing than
Rubik's Tangle 3x3
because one has to decide how to flip the pieces.
from: www.uspto.gov - patent no. 487,798