The Vise® Z87 features an all TR90 construction and tightly holds form and function together, as the Vise® Z87 meets ANSI Z.87 mass-impact requirements (and Z87+ with add on side-shields) featuring 1.9mm thick lenses to aid in protection against basic impacts and flying debris, which enables the Vise® to transcend just that of a regular pair of sunglasses. Our lenses are injection molded from thick 1.9mm shatter-resistant polycarbonate that is built to withstand Z87 Mass Impact Standards. Add on optional side shields for additional lateral protection to meet Z87+ standards. Each pair of Vise® Z87 is boldly marked Z87 on the frame, arm and lens. Disclaimer: Removing arms, and or changing configuration in any way voids Z87 compliance. Heatwave | Vise Z87 Safety Glasses | Vapor Clear Frame