WALL MASTER GALVANIZED EXHAUST FANS 50" Diameter Fan - 1-Speed, Three Phase Belt Drive Motor - Cast Aluminum Blades Eliminates heat build-up in barns, greenhouses and industrial buildings. Exhaust fans feature external aluminum shutters with tie bars to help prevent shutter flapping. Heavy-duty 18 gauge steel housing. Hot dipped after welded, galvanized 1" x 2" x 12 gauge removable wire mesh guards. Includes poly guard clips to reduce vibration. Totally enclosed motor has sealed ball bearings and automatic thermal overload protection. Galvanized X-frame motor mount provides rigidity for long life and quiet operation. 3 cast aluminum blades are balanced for smooth operation. Cast aluminum blades offer low noise operation and withstand bird impact. Exhaust Fan includes a spring loaded belt tensioner, and pre-lubricated, sealed bearings that are rubber mounted to reduce blade fatigue. Exhaust fans include provisions for hardwire installation. Field convertible 230/460V. Motor is UL/ULC recognized. 2 Year Limited Warranty. Horsepower rating based upon maximum speed/load.