Remix of my own design:
[https://www.prusaprinters.org/prints/51862-simple-razor-holder](https://www.prusaprinters.org/prints/51862-simple-razor-holder)

Edit 2021/01/24:
I uploaded the .f3d file so the gap between the backplates is adjustable to your shower shelf. Simply change the parameter backplate_gap to the desired value. I changed the edges to chamfer instead of fillets, cause it looks better imho. Feel free to customize it to your needs.

Default measurements:
Overall height: 40.00mm
Overall width: 52.00mm
Gap between backplate: 3.25mm
Space between the two hooks: 32.00mm
Inner depth of the hooks: 9.00mm

Print instructions

No supports needed

You can pretty much use the default profile for (Prusament) PETG