Ultra Flex eyewear features advanced nylon composite frame with uni-fit ear and nose pieces for comfortable wear. Fits well for those with larger facial features. Includes side shields, available with Rx* lenses. Model 98UF - Front Lenses: 0.75mm Pb Equivalency Optical Lead Glass - Includes Side Shields: 0.50mm Pb Equivalency Lead Foil - Optional Rx*: Single Vision (SV) and Bifocal (BI)