The Option OTG Turbo is the ultimate weapon against fog. Smith's patented 2-speed, micro-electronic fan exhausts hot air and steam from inside the goggle for up to 50 hours on a single AAA battery. Ideal fro eyeglass users, the Option OTG Turbo now includes an additional Yellow, dual-pane Airflow lens in addition to the installed Clear, AFC lens to ensure that you stay fog free 365 days a year.