Features:1. This product is suitable for: Core 300/Core 300-RF and other air purifiers.2. It can filter tiny dust to prevent secondary pollution. It filters the fine particles in the air such as pet dander, dust, and pollen, effectively helping improve allergies.3. Using an air cleaner filter and changing the filter regularly helps optimize air purification performance.4. Quality non-woven + filter paper made, which is durable and no harm.5. It is recommended to replace it every 6 months. Notice:Actual color may be slightly different from the image due to different display and light effect. Please allow 1-3cm deviation due to manual measurement. Description:Material:non-woven + filter paperSize: 20 x 15.5cm/7.9 x 6.1 inchColor/Style: As the picture shown