I am a bicyclist that switches between sunglasses and clear protective glasses depending on ambient light levels (ie. shades during the day, clear safety glasses at night and in the rain).  I clip my small rear-view mirror to whichever glasses I am riding with.  I needed something to carry and protect the other pair of glasses not in use, when they are stored in my bike bag while riding.

This case is the perfect size for both my IronMan sunglasses and my Kazbek XL oversized safety glasses.  It fits either one and protects them well.  Perfect product for what I needed.