The 4x4x6 cuboid was released in 2012, and then the 4x4x6 fisher cuboid 2015. These two puzzles are best-seller puzzles. In Feb 2018, the 4x4x5 Cuboid (center-shifted) was released based on the design of previous 4x4x6 cuboid. To complete the series, there is now the brand new 4x4x5 Fisher Cuboid (center-shifted).
Calvin's 4x4x5 Fisher Cuboid is a brand new design which is based on the design of 4x4x6 fisher cuboid; with the top layer eliminated. Since the center is shifted, you can create quite a few interesting shapes during its turning.