Material: Our lightweight PU Leather material offers comfort and simplicity.Adjustable & anti-slip design: The spectacle chain holder is designed with adjustable end and anti-slip loop, the glasses lanyard holder can adjust to fit your head perfectly.Each neck cord lanyard is strong & sturdy and is not easy to break or twist.Suitable for most glasses: Eyeglass Strap chain is Great for most glasses and fits for all ages of women & men. The glasses holder plays an important role for daily's use, especially sports and outdoor activities, etc.Widely Used: Fit most glasses frames, can work well with prescription glasses, sunglasses, reading glasses, safety glasses, etc.