The Tifosi Optics Seek Sunglasses are so lightweight, you will hardly notice you are wearing them. This pair of Sunglasses has an adjustable eye and nose piece that is made with hydrophilic rubber material that provides you with an extra grip when you sweat. They are built using Grilamid TR90, a homopolyamide nylon material that has an incredibly high bending strength and low density. The polycarbonate, decentered lenses are designed to flex upon impact and will not shatter if they are accidentally dropped. Seek Sun-Glasses are a great way to make sure that your eyes are kept 100% protected from UVA and UVB rays that could otherwise cause permanent damage to your eyes.