Eco-Blu iBall Self-Aligning Knock-In Pool Pump Accessory, 1.5-Inch, White Low Flow Rate: Maximizes flow velocity (agitation & circulation) High Flow Rates: Minimizes restriction or (TDH) of pump Maximize efficiency for all multi-speed pumps Minimize operational expense through improved pump performance and reduced restriction Increases dispersion range resulting in less algae buildup and increased pool chemical performance