This is a genuine Oase replacement cleaning impeller rotor designed for Oase Bitron UV Clarifiers. The rotor works as an automatic cleaning system, constantly cleaning your Oase Impeller. It is recommended to replace the cleaning impeller when signs of wear or damage are evident. This replacement cleaning impeller is compatible with Bitron C18 and C24 systems. Please consult your unit's instruction manual to confirm the correct part. It fits Bitron C18 (56356) and Bitron C24 (56804, 56620). These are genuine Oase spare parts, easy to fit.