 And it has the optical purity of glass. And furthermore, it's extremely light. So that whole pair of glasses in your hand, Keith, if you're holding them, that weighs less than one ounce. And that might, you know, a regular pair of sunglasses you're wearing might weigh three or four ounces. It's something if you just throw them on for a second, take them off, you might not really pick up on. But over the course of five, six, seven hours, that lightweight is going to help relax your eyes more. It's going to be a more comfortable fit long-term.