Dimension---The size of the eyeglass strap holder end is approx. 20 x 5 mm in length and width, universal size fits for most eyeglasses chains, suitable for most people to use. Easy to Use---The eyeglass chain end is a good linker between the glasses and the chain, which is not easy to slip off, the wearer can easily adjust the tightness just by moving the button, sliding up means lock, sliding down means unlock. Anti Slip---These spectacle chain connectors can prevent your eyeglasses from accidentally falling or losing. 40pcs adjustable silicone antiskid rings for glasses to meet different needs and can be used for a long time. Premium Mateiral---Made of durable silicone and stainless steel, high-quality materials, no need to worry about rust and fading. Practical Usages---Perfect for short-eye eyeglass, sunglasses and any craft project that requires an end loop. You also can send them to your friends.