Rule In-Line Blowers Rule In-Line Blower – 3" or 4" Ducting Designed for efficient, high output operation, these blowers feature our exclusive front and rear shaft seals and corrosion resistant motor housings for long life. Compact and easily installed on any flat surface, Rule® in-line blowers provide higher air flow, lower amp draw, and quieter operation than standard blowers. For International & US Markets. Efficient high-volume air flow Quiet operation Low amp draw Slip-on inlet and outlet ducting connections Sealed motor shaft for moisture protection Corrosion resistant nickel-plated motor housing IMCI (CE) USCG 183.410 Compliant: Ignition protected Applications: Race cars and helmet ventilation;Bus ventilation (engine and bathroom fumes);Prison van ventilation (cooling, air-freshening);Blow -up signs and mascots;Tanning booths;Building ventilation