Frame is made of a soft, flexible material, providing additional comfort for long days on the road Flow through ventilation system minimizes fogging by circulating air through the optical chamber. Elastic head strap can easily be adjusted to ensure a safe, snug fit regardless of head size. Meet or exceed the New High Impact ANSI Z87.1-2003strong standards! Complete with a Micro Fiber Cleaning Cloth and Case. Our Lifetime Replacement Guarantee insures your satisfaction.