If there's one thing that drives me crazy, it's when I'm about to give someone a blessing only to open my oil vile and find it bone dry. I've never known a priesthood holder to check his vile every day to make sure he has oil in there, and he shouldn't have to. The see-through feature of this vile assures that you know how much oil you have at a moment's notice. The vile lasts 2-3 years before it leaks from wear and tear, requiring a new vile (and a dry cleaning of your suit pants, which we do regularly anyway). It's inexpensive so replacing the vile is not burdensome.