Ordered this lens just in time for my Challenger goggles. Skied in a couple of snowstorms in Vermont and this lens worked great in the flat light. Switched back to the original lens for bluebird days. Almost no fogging. Swapping lenses is fairly easy, once you get the hang of it, but can be a little frustrating until you figure out the secret, which is the reason I'm giving it four stars instead of five. It also looks to me as if the lens connectors might wear out if you have to swap lenses regularly, but time will tell. If you haven't bought goggles yet, and like multiple lenses, consider a magnetic version like Fathom, where the lens change is instant. One thing about Challenger goggles, they fit my Giro helmet pretty well, which other inexpensive brands have not.