Lens Curve 4C Material: Front acetate and titanium, temple beta titanium Transmittance: 40% The latest version of the metal frame "73/01" announced last year, "73/04" is a design that combines different materials, plastic and metal, known as thermont or combination brow. These combination sunglasses feature a plastic brow, titanium end pieces, and temples that rest on the ears, creating a striking contrast between the different materials. To avoid the harsh look that is common with square lens shapes, the variable octagonal shape and faceted brows create three-dimensional details and a design that is suitable for anyone.