This work was designed as a Christmas present for 2020.
The drawer is locked, and there are two plates on the top.
Please open the drawer completely, while manipulating the two plates.
If you can see the back space of the drawer, you’ve done well.
As the title of this item suggests, two Line Symmetric devices are really used.
In actuality, the same inverted devices are really used.
Two traps are waiting there.