S197 Mustang quarter windows have been available from Ultra-Carbon for a few years now. They may only save a few pounds, but they add a whole lot of cool factor!! They glue into place just like your factory glass. Heck, you could probably use double-sided tape to stick them to your factory glass so they’re removable. They weigh just 7 ounces each. Also available in all the colors we offer for roll bar tube protectors. Find them on the website at the 05-09 or 10-14 Mustang pages!