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. Meets Z.87 Requirements, and Z87+ with add on Side Shields: 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. Lens Technology: 1.9mm thick Polycarbonate lens that meets or exceeds mass impact requirements for Z87 standards, injection molded to the highest standards and tested to ensure optimal clarity, along with color and light transmission standards. We use only the highest quality polarizing filters on our lenses for optimal glare reduction and supreme clarity *Available in both non-polarized and polarized options* Lenses are U6:L3 UV400 - 100% UVA / UVB blocking Firestorm Lens VLT = 14% / Cat 3Firestorm Polarized Lens VLT = 14% / Cat 3 Product Measurements: