API Filstar Canister Filter XP XL Impeller Kit EP23: How to choose the right database? Also Perch le api sono cos importanti per la vita sulla Terra e per l'ambiente Endpoint API Documentation: How to write it & Examples. The Rena Filstar XP4 Impeller Kit replaces your old, worn out or broken aquarium canister filter impeller. Replacing an old impeller is essential to keep your filter running with optimum power and efficiency. Includes rotor, shaft and bearing Fits Rena Filstar XP4 external filter Replaces old or degraded impeller Old, uncared for impellers can result in decreased water flow, poor circulation, and, in some cases, even an unpleasant grinding noise. Replace the impeller to reinvigorate your filter with strong, silent water pull and maximum circulation. Filters and impellers should be cleaned and maintained regularly to extend the life of your parts and system.