Push the transparent holder part into the arm's wrist.
 
Then add a 16mm screw to secure the holder in place.

Now attach the wall mount to the wrist, use a square nut on one side to screw everything together.

No add your SGL small panel, you can attach it thanks to two zip ties.

You can either use hot glue or double-sided tape to attach your panel to your box.
 
It's advised to have the pot already in place when choosing their position, the lowest panels should be at least 15cm higher than the pot if placed on a wall.

Once the holder is glued to your furniture you can tighten the screws.
 
Don't over tighten is tho, just enough for it to stay in place.

For vertical lighting: Don't put your panels too low.

Make sure there's some space between the top of the pot and the lower panels.

Of course those panels can be used with any flat surface.

Best is to place them so the plant has good coverage from different angles, which is the key to maximum yield per watts.