It takes a lot of force or being heavy to sit on it to tighten the wood. It has wooden wedges and they are difficult to fasten. A large hammer will be useful.

Also, the screw system is a bit strange. If you don't tighten the internal ones to the right depth and fasten the wood from above with the wedges, then the external ones don't hold and you have to call Superman to open it again. A good solution is to have a sturdy screwdriver, for example, a chestnut one with tips to turn the external screws and catch them crookedly. And as shown in the photos, they don't have covers to hide them and they stand out a lot in black.