Bikemom, you refer to "customers." What is your profession and do your customers mountainbike or ride in dusty environments? The 2 layers trap a lot of dust (I can hardly keep one layer clean) and the distortion can be a problem. Just curious what your customers use the fitovers for.

They are great for more normal daily use, for instance for people with cataracts. My MIL will hardly leave the house without hers but then she's not trying to see little bitty pebbles on the pavement from a skinny tire at high speeds.