5MAG lens retention system Soft goggle frame for unparalleled comfort and fit OTG, Over The Glasses, compatible Shuttered Venting in frame scoop air in or closes off flow Improved tints, low light, and contrast improving technologies including polarized, HCS, and photochromatic also available The 509 Sinister X7 Snow Goggle is the next evolution of our Sinister series. With its quick-change magnetic lens system, wide field-of-view, cylindrical no fog lens, and frame shuttered venting for even more airflow, these goggles are ready to handle a wide range of weather and snow conditions.