I needed a small shelf that I could screw in the existing holes that the previous renters had left in the bathroom, to put my phone while taking a shower.

• It is designed to not need any supports and don't have any visible screws.
• I used M4 screws for the mount
• The shelf is 170mm*100mm
• Printed with Prusament PETG Galaxy Black
• If you want to edit the model, here is the link for onshape. And I uploaded STEP files.