Costa Del Mar C-Mono Grippers are modern, ultra-light sunglasses retainers. The C-Mono Grippers are constructed of high grade monofilament and swivel hook attachments that you connect to the back of your sunglasses. This will only work with the following Costa frames: Cat Cay, Cut, Howler, Luke, Mag Bay, Playa and Rooster. These retainers provide a high level of protection from lose due to the ultra secure connection between them and you Costa sunglasses. Costa Del Mar C-Mono Grippers look as good as they perform! They have an extremely thin profile and they are so comfortable you'll forget they are there!