My wife and I bought a little shelf by OXO that is designed to go into a medicine cabinet. The idea of the shelf is it allows you to store smaller items inside your medicine cabinet without wasting the whole shelf. Think of it like a half length self.
The problem we ran into is OXO stopped selling it on their website. I figured since I have a 3D printer I would print one out.
The whole thing is 5 1/8" tall (131mm), 6 3/8" wide (161.6mm) and 3 1/4" deep (82.7mm). I printed mine laying down with the curved top portion facing my cooling fans.
The nail file holder is one of my other creations:
Filament is Just PLA's turquoise:
I printed mine laying down with the curved top portions facing the cooling fan to keep them from sagging.
With how mine printed out all I had to do was place in medicine cabinet and enjoy the extra room.
I designed this by using Tinkercad and the existing OXO medicine cabinet shelf