Croakies Terra Spec Adjustable Eyeglass Retainer, Black, Woven Nylon Croakies Terra Spec Adjustable Croakies Terra Spec Adjustable Rope Eyeglass and Sunglass Retainer Croakies Terra Spec Adjustable Eyeglass Retainer, Black, Woven Nylon. Thanks to the universal compatibility of our Spec ends, Terra Spec Cords fit the widest range of eyewear styles. Made with a high quality durable woven cord and featuring an adjustable slider bead for a secure fit when chasing your next adventure. Features Available in Spec Ends Durable woven cord Adjustable black bead Colorfast & washable Sizing O S (One Size) universally compatible, fits a wide range of temple sizes 12 long (each side) by 3. 2mm (diam.)