Fueled by a lightweight strap mounted 7.4V 2200mAh rechargeable Lithium-ion power pack, the entire surface of the lens quickly heats up to 104° F, the Ignite quickly eliminates fog with a single button in either two minute auto mode or ‘always on' mode. A continuous run time rating of 4-5 full hours at max temp ensures you are fog free all day. Simply recharge the pack for tomorrow's ride.