The reason is we're really confident in our ability to get people where we think they should be, and we're confident because we track data. We've seen people over the years, and we've collected all these numbers over the years. And we know what the probability of us being able to get somebody to the 20/20 level is, provided their eyes are otherwise healthy. If their eyes aren't otherwise healthy, we're not going to operate on them anyway. And we do a thorough exam, and if for any reason we find that you may not reach this 20/20, we tell you beforehand, not after. If there's a small group of patients, no matter who they are, just take a large enough group people, there will be a small group of people that even when the procedure is perfect, they're going to regress a little bit because their immune system, their healing system and response is a little different. Well, that's why we make sure that that patient has the right corneal structure and the right tissue amount to be able to go back and do a touch-up or fine-tuning if they need to. You know, a lot of people play golf. We one putt rather than ninety five percent of the time, but occasionally we have to do a one-foot tap in, and so, you know, but we're good at the tap ins, and that's why we can offer the 20/20 or your money back, because we have a really very high probability of knowing who's going to be able to get there. And that's how we did the 20/20, why we did the 20/20 or your money back program. Letting patients know when we're very confident we can get them to their goal and our goal.