5mm Universal Fit Rope Eyewear Retainer by Chums®. Chums 5mm Universal Fit Rope Eyewear Retainer are made with molded tips that fit nearly any size of eyewear frame without your frames slipping. The nylon rope construction gives this retainer unique strength, durability and style. The 5mm nylon braid is fully adjustable with the sliding bead. Comes in various colors. Made in the USA.