Shield Sunglasses by Foot Forward Sports introduces CLOAK - Our super lightweight, ultra durable, face contouring frame made of TR90 material. TR90a Swiss technology thermoplastic material is incredibly durable, flexible, and lightweight. This makes our Cloak sunglasses extremely comfortable because they have that flexible quality and can bend under pressure and contour your face comfortably. TR90's flexibility also makes Cloak resilient to damage. Because the material is pliable, they are far less likely to break or bend from impact. If you're guilty of constantly dropping your glasses, fear not! Cloak will prevail! Finally, and most remarkable of all, Cloak sunglasses are supremely lightweight without sacrificing strength! The thermoplastic material has a barely-there feel that you truly have to wear to believe.