This long-life battery pak and charger now has infinitely high-low control. Pulse width modulation extends battery life up to 10 hours in low setting yet gives a full 2.5 hours on high. Can be used on a vehicle battery with an optional connector. Built-in charger allows you to fully recharge the battery in 12 hours. Purge the area on high for 10 minutes, reduce to low speed (low-noise as well) and maintain fresh air for the whole work shift. Ideal for construction job sites to eliminate noisy gasoline-engine blowers. High-low control enables fast-purge ventilation and lower speed for maintaining safe work space. High impact case includes battery and built-in charger for overnight charging. Up to 10 hours of continuous operation. Lightweight and portable.