Initially the old technology has the advantage. Why? It’s more reliable. It's well-known, well understood. There's plenty of service technicians around. It's reliable. And but as initial problems are solved, of course, it begins to substitute for the other. New technology adoption typically occurs application by application. It usually finds an application that the other technology does not serve well. And usually it's not very attractive to the current provider. So it's usually a typically small niche. And in surgery it actually occurs surgical procedure by surgical procedure because they're quite different. And so you know it looks like this. You probably all seen this. You know Jeff Moore wrote a book "Crossing the Chasm'. Starts out with innovators. Those guys are easy to sell, but it's hard to maintain their attention. The early adopters come along. They're willing to tolerate a fair amount of fiddle factor inconvenience. And their attention's a little earlier, a little better, but they're always looking for the next thing. And then you begin to use the early majority and they won't tolerate much. I mean they want it to be as fast. They just will not tolerate much fiddle factor. And then ultimately you get to the lay majority and finally the laggards who come kicking and screaming. Only because they can't do it all the way. It's no longer available.