The idea of product is invented by a father who promises to make a toy that his kids can play all the time. That’s why the puzzle comes with metal material and is connected by screws. It looks easy but you have to fight to put all pieces back as a cube.  
This is for the Grey Cube
Material: Aluminum alloy
Special point: blocks are connected by screws, so you can create your own puzzle
Multi-function:
1. Play puzzle 2D or 3D
2. phone stand
3. art statue

• See at Puzzle Master