Johnson Pump In-Line BlowerJohnson Pump In-Line Blowers provide ventilation for bilges, engine compartments, galleys, and heads. Available in 3" and 4" sizes, these blowers are made from high quality ABS plastic construction, corrosion-resistant motors, and premium electrical connections. Johnson In-Line Blowers are compact and feature mounting feet that make installation easy on any flat surfaces. Five blades; Quiet operation; Highly efficient; Reliable operation; Specifications: 3" Blower; 12V; Capacity: 158 CFM; Port Connections: 3"; 4" Blower; 12V; Capacity: 240 CFM; Port Connections: 4";