I'd been wishing my glasses cases had hooks so I could clip them to bags and stuff. Finally decided to just see if there's a good one out there, and I'm SO glad I found this one. This case is harder/more durable than my zipper case, has a carabiner (with full 360-degree swivel-ability) already attached, isn't falling apart like my clamshell hard case, AND came with some extra stuff I wasn't expecting because I didn't read the description that closely. I have a couple different pairs of sunglasses, and I'm definitely going to upgrade my other cases to these. My biggest glasses/sunglasses fit in here no problem, but the size feels great—not too big or bulky. Exactly what I wanted.