Rule 500 "STC" Tournament Series Straight Thru-Hull Inlet Fitting This new pump builds on Rule's unsurpassed quality and leadership in pump design and technology. The innovative design includes many exciting new features including a quick, easy-to-use motor cartridge removal system, swivel base that allows you to position the discharge nozzle anywhere, and threaded nylon hose barb fittings that allow for various hose mounting options. Other features include a built-in dual-port option, water-cooled housing, and positive snap-on motor cartridge locking mechanism.