Pack of 12 pcs Colorful Unisex Nylon Cord Braided Sunglass Keeper Eyeglass Safety Neck Strap Chains Lanyard Eyewear Retainer Rope Holder (12 pcs Thin) Package included 12 pcs colorful eyeglasses holder strap Made of Nylon material Good for presbyopic glasses,sunglasses etc. Total length: Approx.23.5inch(each) After passing through the glasses frame, Please push the coil to lock and avoid falling off