The Bliz Velo XT Sunglasses are ideal for sprinting up trails, speedy cycling, and hitting the cross country ski track. Bliz included three pairs of lenses for bright light, low light, and no light. These Unbreakable Polycarbonate lenses are ten times more impact resistant than standard plastic or glass lenses, and the grilamid TR90 frame is flexible, superlight, and surprisingly strong. There are adjustable nose and temple grips for a secure fit, or you can switch out the temple tips with the goggle like strap for an even more secure fit. Proposition 65 Warning for California Consumers: This product contains chemicals known to the State of California to cause cancer andor birth defects or other reproductive harm.