Designed to eliminate problems unique to sleeding, such as fogging in cold weather and maintaining visual clarity in varying light condition. All Smith snowmobile goggles come with a dual-pane lens that increases light transmission, giving improved visibility and definition. PMT(Preforated Memebrane Technology) lens helps keep goggles fog-free even in the worst weather. Adjustable, silicone-backed straps keep goggles securely in place. Snow Turbo Option OTG sets the standard for anti-fog goggles with its two-speed electronic fan. All lenses have anti-fog coating. All new large size frame also accepts existing Cariboo/SMX/SME lenses. Extended FAT two-layer face foam. Dual-pane yellow PMT anti-fog lens standard. Woven, adjustable silicone-backed strap.