This case offers enough space for my large sunglasses. A bit bulky when tied to a belt, but I don't like it hanging on a hook and swaying as I walk. I also clipped it to my backpack and it's very convenient on and off the trail. As others have pointed out, it doesn't open wide, you have to press hard to keep it wide open to insert or remove large frames. Make sure the zipper is fully open so it can be opened wide. I worry that one day the lenses might get scratched by the zipper. Otherwise, it is durable and protects your glasses well.