Ideal for opening 50ml and 100ml Botox bottles. There may be cheaper ways to open vials, but when a vial costs the same as botox, I want to use the right tool! It's easy to make and I'm not worried about breaking the bottle. I've seen other versions of this online that cost about twice as much but are only one-sided. It works both sizes in one tool at a good price and I can't imagine any other tool doing better than this. This tool appears to be very durable and well made.