Eyewear Retainers: Anti-slip Eyeglass Chains Lanyard is designed to keep a tight grip on your eyeglasses, preventing the loss of the glasses and breaking during movement or sports, allowing your eyewear to be comfortably hung on your chest, or rest on top of your head. Adjustable Design: Eyeglass straps are approximately 32cm/12.6inch, the size of the hole is about two millimeters and the black toggle switch on the cord adjusts to your head size, pull it tight against your head so that the eyeglass string strap fits everyone's head shape. Hand Wash Only Fastening: 4pcs Beaded Eyeglass Chains for Women & Girls Adjustable Eyeglass Strap, Sunglasses Strap, Sports Glasses Band, Eye Glasses String Strap Around the Neck Beaded,Toggle Premium Material: The eyeglass lanyards are made of premium spandex and plastic non-slip buckle, which has good breathability and moisture discharge. The eyeglass cord strap is stretchy, and not easy to deform, age, or break. Wide Application: Colorful glasses straps suitable for outdoor sports such as running, playing ball, and cycling; Great gift for anyone who owns sunglasses, presbyopic glasses, or others. According to your mood, match your various clothes. Package Content: you will receive 4 adjustable eyeglass straps. Our glasses lanyard includes 4 different colors green, blue, purple, black, and orange which can match glasses and clothing of different colors, making you look more fashionable.