Zeal Optics Tenacity ZB-13 Polarized Sunglasses Overall our consistent MOST RX'd Zeal frame. Classic good looks never go out of style. ZB-13 Polarized - One Lens Maximum Versatility! Outside Magazine's BEST SUNGLASS 2006! The ZB-13 Polarized lens "amps up depth perception, intensifies contrast, sharpens edges, and performs masterfully in so many light conditions." "No Fee" Lifetime Warranty & Crash Replacement Program direct with Zeal Optics Complimentary "recycled" BONUS hard carrying case and microfiber cleaning bag. Afford yourself the luxury of uncomplicated, quality eyewear for clear vision.