Demo:
Attach mirror to your shower pole whenever you need it.
Rod diameter 23mm (20-24 would work).
Dimensions: 125,5mm x 40mm
Instructions:
Slider and clip fits together, you can use glue if it is loose, or a little bit of heat if it is too tight.
Rubber band is inserted through the holes using tweezers. I recommend to put some thin rubber in the surface where the pole is if you have weaker rubber band.
Enjoy!
Mirror used: https://www.ikea.com/gb/en/p/loensas-mirror-30473696/
The author hasn't provided the model origin yet.