For those riders who like the style of the Original KD's but are looking for a larger frame, the X-KD's are 20 percent larger. Polarized lens sunglasses offer better function and versatility than conventional sunglasses. Polarized lenses dramatically reduce reflective glare off of water, highways and other reflective surfaces. Eye fatique associated with prolonged exposure to the sun's glare is effectively diminished. This black framed sunglass has been extremely popular with bikers for over 60 years because they stay on your head and keep the wind out of your eyes by fitting tightly on the temples and nosebridge. And most importantly, KD sunglasses look great on men and women.