ActronAir Drain Pump Washer provides the sealing washer for the CRE series drain pump connection to prevent leakage at the pump fitting on CRE series wall split systems, ensuring reliable condensate removal that prevents water buildup and overflow damage to the indoor unit installation. Replace the drain pump washer whenever the drain pump is removed -- reusing an old washer risks condensate leakage at the fitting. Ensure power is isolated before accessing any indoor unit drainage components.