FRAME FEATURES: RB3731 Anh sunglasses feature a butterfly, light gold frame with angular edges and dark grey bio-nylon lenses. SUSTAINABILITY: The Bio-Nylon lenses are made with 40% bio-based materials derived from renewable sources such as castor oil. 100% UV PROTECTION: To protect your eyes from harmful UV rays, these Ray-Ban sunglasses include lenses that are coated with 100% UV protection. CASE & CLEANING CLOTH INCLUDED: Each pair of Ray-Ban sunglasses come with a cleaning cloth and case to clean and protect your sunglasses from scratches and damage.