Angel's PFS (Prism Free System) polycarbonate sun lenses are precision-manufactured to produce an extremely consistent lens surface of ultimate quality. The ultra light, shatter-resistant lens offers 100% protection from UVA and UVB radiation and exceeds all ANSI standards for optical clarity and impact-resistance. Frames are lightweight cellulose propionate. Planning to wear your Firestars on the water? Consider a floater.