I have tried many roller bottles over the years for my perfumes that sometimes come in unwieldy bottles. Most rollers don’t seal well, or don’t apply well. This one is PERFECT. It seals with a satisfying “click”, and has a fairly large roller ball surface that applies a good amount of the liquid, but not too much. Well controlled. From the first time I used it, I had to order more to have on hand. I am enjoying my perfume so much more! Thank you, Infinity!