Automatic swimming pool cleaners and components thereof are described. The cleaners may provide dual filtration of debris suspended in water of pools as well as a fluid path allowing some water to by-pass one of the two filters. They also may include any of all components such as multi-section inlet tubes, Venturi jets, nozzles exhausting water onto rotatable vanes, brushes, downforce turbines, and mechanisms for adjusting water flow through thrust jets or sweep tails.