Chums Switchback Sunglasses Retainer - The new Switchback Silicone Eyewear Retainer is a one-piece molded retainer. The temple ends can accommodate a wide variety of eyewear via its two-port design: one port for larger frames and one port for smaller and wire frames. Features Non-absorbent and stretchy; Top port fits wire frames; Bottom port fits standard and large frames; UV and corrosion resistant; Multiple attachment options both right side up and upside down;