Calvin's 4x4x6 Cuboid by TomZ
Calvin's 4x4x6 Shapeshifting Cuboid Puzzle by TomZ
This Iconic shape shifting cuboid puzzle was designed by the puzzle design genius TomZ and mass produced by Calvin's puzzles. The definitive cuboid puzzle on the market at the moment, it shapeshifts in all directions, has multiple parity possibilities to wrap your brain around, and looks very intimidating when scrambled.
One to keep any puzzler happy for many hours.