The Anon Men's M2 Goggles with Spare Lens features Magna-Tech Quick Lens Change Technology, using 16 powerful neodymium magnets to make lens changes easier than ever. Spherical Lens Technology mimics the curvature of the human eye for superior optics, while SONAR lens technology by ZEISS enhances contrast for the best possible definition and terrain recognition. Magnetic Facemask Integration (MFI) seals Anon's MFI facemask accessories (sold separately) to the goggle in a snap. Full perimeter channel venting ensures maximum airflow for clear, fog-free vision in all conditions. Includes spare lens for cloudy conditions, and microfiber goggle bag for storage and cleaning the lenses. ANON Men's M2 Goggles with Spare Lens