Very nice 3D printed puzzle, which is equivalent to a siamese 2x2x2 with the additional feature of turning the middle layer. A very attractive idea. The puzzle looks easy to solve, but indeed it is not as trivial as it looks like. The mechanism turns very well, but at half way of the moves around the yellow/orange axis the end pieces might fall off, because only the rough surface of the printed pieces hinders them from twisting out of the mechanism. Anyway, not a very big problem. Some small bumps and holes between the inner surfaces could help to hold the pieces and fix this issue.