"You can try this product in-store before purchasing online. Visit our physical store to experience it firsthand!" - Contact us for Available Store Location + Get A Free Eye Test " -- PREMIUM NYLON CORDS: These eyeglasses cords are made from a high-quality nylon material that easily grips well on your frames. Not easy to deform, not easy to aging, not easy to break, and durable. These Cords are easy and comfortable to use.