TITUS 50mm Welding Lenses and Goggles (Lenses w/ Goggles, #09) Custom Darkness: Choose the dimming you need! The higher the number, the darker the lenses. Adjustable Width: Adjust the goggles to your preferred comfort fitting. Replaceable Lenses: Switch out your lenses with any 50mm standard lense. Certified: Exceeds ANSI Z87.1 standards and conforms to CE EN166 regulations. Durable: Includes a hard-coated poly-carbonate outer lens to protect your glass lenses and resist scratching.