The main user interface is a simple small orange plate.
It’s not the buttons but the RFID reader that makes the device special in terms of user interaction.
In the top plate’s center there is a little orange piece of plastic holding the RFID reader’s antenna. The thickness is reduced where the antenna operates so that tags may be detected reliably. Magnets arranged in the corner of the antenna will hold the tags in position. Magnets with a diameter of 8mm will fit in perfectly. The number of magnets can be changed without printing a new part as they are held by screws.
This orange RFID center part is then attached to another 3D printed piece of plastic. The latter one fits on top the LED ring and is held there from the bottom of the whole box via four screws.
Printing went flawlessly.