TPI Belt-Drive Exhaust Fans and Wall Shutters exhaust stale, hot internal air and replace it with fresh outside air. Belt drive exhaust fans have 120V, 1-ph. ball bearing, permanently lubricated, drip proof motors. Also include: permanently lubricated bearings on blade drive shaft, steel blades, powder coated venturi and blade, and weather-stripping for tight seal. All-aluminum shutter offers air-open and gravity-close operation. One-year warranty. Made in USA.