It was designed for these refillable squirting bottles you can get at the dollar store with a diameter of 55mm.
I use it in the kitchen to keep the refillable bottle with dish soap out of the way and it works very well. I glued it to the wall using gecko tape which I recommend you use as well and it has not fallen of in a couple of months.
But you could use it for all sorts of fluids like cooking oil or vinegar.