Jabsco 4" 250 CFM Flangemount Heavy Duty Blower - 12VHeavy Duty Flangemount Blower Heavy 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