Introducing the Ignite heated dual lens technology by 509. The Ignite heated lens provides the ultimate in fog prevention technology. Fueled by a lightweight strap mounted 7.4V 2200mAh rechargeable Lithium-ion power pack (not included), the entire surface of the lens quickly heats up to 104? F using a transparent thermal conductive ITO (Indium Tin Oxide) layer on the inner lens. Evolved from military aircraft windshield defrosting technology, the Ignite quickly eliminates fog with a single button.