Ray-Ban RB3721CH Chromance are a new generation of sunglasses. The square metal frame has been designed to withstand the test of time, while maintaining an innovative and unique style. These unisex shades feature grey polarized chromance lenses that provide color and contrast enhancement for a vibrant look. With their black on black metal frames, these glasses offer both comfort and style so you can stay sharp all day long. Available with lens contrast enhancement technology.