Designed by John Harris, circa early 1970's.
(plastic, each cube is 1" square, box is 3.5" x 3.5" x 1.25")
Eight identical cubes can be flipped around
(via the ridges on the tray);
the go al is to mix them up and then restore to have the same color on top and the middle empty.
This puzzle is similar to
The tiles snap off if want to make a different puzzle.
presents a solution and describes the puzzle,
noting that it was discussed in
Martin Gardner's Mathematical Games column in Scientific American March and April 1975.
He also notes that the designer is the same person as that for