Utilizing advanced fan blade design techniques, Attwood has developed a blower system that matches air flow of existing in-line blowers at a significantly reduced noise level. The first vane axial-flow fan bilge blowers designed using aerospace technology to maximize performance. No other bilge blowers in the industry provide such powerful system output at such a low power input in a compact size. Patented in-line design - provides ventilation for engine compartments, galleys, bilges, and heads. Mounting feet allow vertical or horizontal installation in confined spaces. Install with #10 fasteners. Individual carton includes 2 tie straps. All are CE certified. 16-gauge tinned and caulked copper wire leads. Features: Nickel-plated motor can for corrosion resistance Stiffening ribs to reduce housing distortion Five-blade fan maximize airflow and efficiency Tabs in intake and exhaust hold ventilation hose/clamp firmly in place Low amp draw motor for longer blower and battery life Built-in mounting feet allow easy vertical or horizontal install 3-Year Warranty Ducting = 4" , Open Flow (CFM) = 200 CFM , Volts = 12V