This rotor/impeller fits the Rena Flow 1100, 900 and many classic rena pumps including the S40, C40, S40T now discontinued. Flow may vary slightly =/- 10% from the original rotor that came with any of these pump models. This is the only rotor available for any of the pumps listed above. It also fits the Rena SmartFilter 55 aquarium filter. Impeller color and number of blades may also vary from the original rotor/impeller. Flow rates may also vary from the original rotor included with your pump. Generally higher volume pumps will have lower flows and/or lift.