Designed this clip to clip my sunglasses to my cars sun visor when not in use. It works very well for my sunglasses.

Update:
For places that get hotter PLA will likely melt a bit and cause the model to bend. Comments typically recommend Nylon or ABS (thank you, everybody). I also posted a new version not necessarily to replace this but its a different design that should be better at holding the sunglasses and not warping quite as much.

V2:
https://www.thingiverse.com/thing:4299084