Polaris Anzen Air Blowers are thermally-protected and shut off automatically under excessive operating temperatures, protecting against motor damage. The auto-reset restarts the motor automatically after cooling. A polyester electrostatic coating, applied inside and out, protects the steel housing against rust and corrosion in any environment. The Polaris Anzen Air Blowers are designed for minimum sound levels and maximum efficiency. The built-in check valve adds protection against blower damage from water surges. The rugged all-steel construction of the Polaris Metal Blowers has been an industry standard for years. These units are covered by a one-year limited warranty.