Speed-Clip system facilitates quick strap adjustment Adjustable Ventilation System (AVS) 2 modes: dust-free, fully-sealed mode or a fog-free, open-ventilation mode 100% UVA/UVB protection The ESS Influx FirePro-1977 FS wildland goggle features the patented Adjustable Ventilation System AVS, for either a dust-free, fully-sealed mode, or a fog-free, open-ventilation mode. The patented Speed-Clip system facilitates quick strap adjustment, even with gloves on. All goggle components are heat and flame resistant, including the durable OpFoam face padding. The Influx FirePro-1977 FS is certified to meet the NFPA 1977 wildland fire equipment performance requirements, NFPA 1977-2011 Edition, including the 350?F for 5-minute oven test. They are also U.S. Federal OSHA compliant, exceed the requirements of ANSI Z87.1-2015, and are considered Primary Eye Protection by NFPA 1500. Additional Key Features: Advanced ESS ClearZone FlowCoat coating eliminates fog inside & prevent scratches outside, interchangeable distortion-free 3.0mm high-impact polycarbonate lenses, U-Rx Insert available, 100% UVA/UVB protection.