Johnson Pump Cartridge Bilge Pump. The details: Compact, all-in-one motor / impeller unit; No tools needed for maintenance; Extremely energy efficient; Water-cooled motor for long service intervals; Meets the international standard, ISO 8849 marine; 3/4" hose size. Available in 500 GPH or 750 GPH. State Size. Order Yours Today! Johnson Pump Cartridge Bilge Pump