Poly-urethane patented formula we use on our headlight restoration. The result a lens that return reflective light rays, is clear tinted to the original color and smooth and glossy like new. We test our products in the field as well as in the lab under the same conditons with the atmospheres' elements and exposure to sunlight and other contaminates. Our product stands up to perform as well as the original product or reproduction replicas. The other side of the coin is that your vehicle is original wether it be a '57 Chevy or 69 Mustang looks the same as it did off the showroom when it was new and it is the original factory part. You decide.