IVC filters were designed first on a permanent basis to stop blood clots from causing further damage in other areas of the body. And if you can imagine just kind of like a spider apparatus that’s put in a vein to stop blood clots in its tracks. And then they became non-permanent or on other words, you could take them out. So essentially from a very broken down or basic concept you got a piece of barbwire in someone’s vein that’s stopping a blood clot and either they don’t work, they break off, they migrate, or they actually travel to another part of the body. We’ve got several cases where they’ve had to have open-heart surgery because a leg fractured and impaled itself in the side of the heart as the blood was pumping through.