Works OK
Seems they leek a bit. I filled mine with an oil and it is pretty messy oozing oil and dispenses quite a bit at once. I put the roller top on the bottle as tight as I could get it and it still leaks.
Our roller ball bottle is a heavy style glass bottle with a frosted roller ball fitment and black caps. Roller ball bottles are super easy to fill; just don't overfill them! Room is needed for the ball fitment to be inside the bottle. I have made lip gloss, perfumes, and therapy oils which I have put in a roller ball bottle. Please don't exceed 10% scenting oil load, and it just isn't necessary. Most scenting oils (either essential oils or fragrance oils) are much better in a diluted state anyway.
The bottle is clear glass and solid. This is not an ultra thin glass bottle. A simple setup for perfume or anything else you want to roll on.
The bottle holds approximately 10 mL.