The file '‘Split’ 1x2x3 3D Printer Model' is (STL) file type, size is 45.3KB.
This is a 1x2x3, where the top and bottom layers have been sliced in half, allowing for 90 and 270 degree turns as well as 180 and 360 degree turns on those layers. This make the puzzle behave like a 2x2x3 bandaged along the middle layer in two places, thus making it far more difficult than a 1x2x3, or even a 2x2x3, for that matter.
1x2x3split.STL | 179.8KB |