I've never heard of such a mirror, but as I've said on other threads, my trick is to spit on the mirror (yes, gross), and smear it around. Then when I'm ready to shave, I just rinse the mirror off. It stays fog free for the whole shave, and I only invested probably 10 bucks or so from Wal-Mart. This trick also works for goggles or diving masks. I can't explain why, but it does.