The Fluval A15641 is an official replacement impeller and shaft assembly.

It is specifically designed for classic Fluval canister filter models, primarily the Fluval 103 and Fluval 203. 

The impeller is the only moving part inside the filter’s motor, driving the water flow to ensure proper filtration and water quality. If your Fluval 103 or 203 filter is struggling to pump water, making a loud rattling noise, or failing to spin, replacing the A15641 impeller assembly often restores the filter to its original working condition