Product Details: Condition: New in Original Packing Box Weight: 29g/pair Specifications: 1 glasses case & 1 glasses cloth 1 glasses bag, 1 glasses rope & 1 glasses band 1 polarized lens test card 1 pair of polarized lenses & 4 pairs of interchangeable original£¨Not polarized) lenses Inner frame for shortsighted lenses Features: Free to resend an new one if the glasses broken in one month. INTERCHANGEABLE LENSES POLYCARBONATE LENS MATERIAL Polycarbonate is the extraordinarily durable thermoplastic that's used in bullet proof glass, riot shields and astronaut helmets. It's the ideal material for performance eye wear because of its high impact resistance, inherent UV protection and light weight. All of our lenses are made of polycarbonate. POLARIZED LENSES Our Polarized lenses are made using an injection process that ensures they¡¯re optically correct, decreasing eye fatigue and increasing comfort. As with all of our lenses. Polarized lenses provide protection against 100% UVA, UVB, UVC and harmful blue light to 400nm. Product Maintenance: Don't use alcohol or any other chemicals to clean the lens, to avoid surface broken. And don't maintain the sunglasses in such bad environment of high temperature or long time damp, to avoid deformation. The lens of RockBros Sports Sunglasses is of high technology coating, so regular cleaning maintenance by water is suggested, to make sure good quality could be kept and life time extended.