Introducing Heat Wave Visual's first pair of sunglasses produced in the United States. We have partnered with the most prominent domestic eyewear injection molding facility in California to achieve the perfect balance of build quality, fit, and value. Please note: The USA VISE is NOT compatible with the Vise Side Shields Our lenses are injection molded from thick 1.9mm shatter-resistant polycarbonate that is built to withstand Z87 Mass Impact Standards. Each pair of USA made Vise® is boldly marked Z87 on the frame, arm and lens. The USA Vise builds upon the Vise® legacy with a lightweight Grilamid TR90 premium thermoplastic frame that is uncoated and polished, offering a high luster gloss finish. The uncoated nature of the frame enhances resistance to chemicals, while the TR90 material is overall more durable and flexible. Two traditional high-quality 5-barrel hinges in gold plating securely hold the entire assembly together, contributing to the overall premium fit and finish. Lastly, the USA Vise meets ANSI z87 requirements and includes custom embossed markings on the inside of the temples. Lens Technology: 1.9mm thick Polycarbonate lens that meets or exceeds impact requirements for Z87.1 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 UV400 - 100% UVA / UVB blocking Meets Z87.1 Standards Black Lens VLT = 13% / Cat 3Black Polarized Lens VLT = 13% / Cat 3Gold Rush Lens VLT = 12% / Cat 3Gold Rush Polarized Lens VLT = 11% / Cat 3Sunblast Polarized Lens VLT = 13% / Cat 3Ultra Black Lens VLT = 6% / Cat 4Ultra Black Polarized Lens VLT = 6% / Cat 4