Saje diffuser blend rack

My wife wanted something to organise her assorted collection of Saje diffuser blend bottles which came in three different sizes; 30ml, 10ml and 5ml. The goal was to see the bottle labels but only take up a small amount of surface space while still looking clean and simple.
This very simple design allows for the shelves of different sized bottles to be switchable.

The rear slots double as both extra supports and a place to keep different bottle size shelves. The images show my first version with only one rear support, but I uploaded a version with 2 rear slots.