The Magpul Helix is designed to support your active lifestyle in all conditions by providing superior clarity" contrast" and impact protection whenever you need it. No matter what you're up to" the rimless design gives you an uncompromised field of view" breathability" and professional-grade eye protection. The Helix excels in humid or wet environments where moisture and condensation cause normal lenses to fog or collect water. Its lens and frame design sheds sweat and moisture" keeping your field of view clear. The interchangeable lens system also allows the wearer to transition to lower-light operations with a clear lens or facilitates easy replacement of the lenses when needed. like most of Magpul's eyewear line" the Helix is ballistic rated to Z87+ and MIL-PRF 32432 standards" and the lightweight frames are constructed of TR90NZZ for strength" flexibility" and impact protection.