Heavy Duty Flangemount BlowerHeavy Duty Blowers are designed for applications such as commerical or high use engine room ventilation and extraction where a long life requirement demands heavy duty motors with long brush life. Built to provide the same high outputs as our standard specification blowers. 5,000 hr motor life for the heaviest of applications Continuous duty Efficient high volume air flow Outlet flange mounts directly on bulkhead Slip on inlet ducting connection Low current draw Corrosion resistant materials throughout Dimensionally stable quiet running Delrin rotors Complies with USCG 183.410 and ISO 8846 MARINE (Ignition Protection) ISO 9097 MARINE (Electric Fans) WARNING: This product can expose you to chemicals including NICKEL (METALLIC) which is known to the State of California to cause cancer. For more information go to P65Warnings.ca.gov. Specifications: Ducting: 4" Open Flow (CFM): 250 CFM Volts: 12v Box Dimensions: 11"H x 12"W x 14"L WT: 6.75 lbs UPC: 671880522694 Owner&';s Manual (pdf)