The 509 Aviator 2.0 Ignite Lens tints make it easy to adapt to any condition and feature heated technology for the ultimate in fog-free performance. Simply push a button and the lightweight, strap-mounted rechargeable lithium-ion power pack quickly heats the entire inner lens surface to 104° F. The system features a 2-minute auto-interval mode or ‘always on’ mode, along with a continuous runtime rating of up to 5 hours at max temp for clarity that goes all day.