Aluminum frame is made from super lightweight metal. Triacetate (TAC) lens is a flexible yet tought material. The polarised wafer is chemically fused between two layers of TAC film creating a 1.0mm thick lens. Includes anti-scratch and anti-reflective coating. Lens are also hydrophobic which is a multi-functional clear coating treating that provides salt water resistance for up to 72 hours and acts as a dust, water and oil repellent, making it much easier to clean stains, dust, finger marks and smudges off the lens. Maximum UV protection.