This glasses retainer is a Good solution to hold your glasses tight when doing sports and An Cheap Insurance for your Expensive Sunglasses. You don't want to drop your hundreds dollar glasses. And prevent your glasses losing or falling breaking during Sports like Running, Biking, skiing and so on. And this eyewear retainer can perfectly attached to your glasses temples. This glasses strap is Easy to install. You can easily insert the glasses temple into the ends and slide through. The material is soft and it will not hurt your glasses at all.