COMPATIBILITY - Our Core 400s-RF-PA replacement filter Pet is for Core 400S Smart Air Purifier. Compared to Part #Core 400S -RF, LRF-C401S-WUS. FILTRATION - Our Core 400S filter is designed in H13 True HEPA Filter, high-efficiency activated carbon, and fine Nylon Pre-Filter that helps to reduce airborne particles down to 0.3 microns and neutralize odors, cooking, and wildfire smoke, and VOCs, improved air quality. Our Core 400S filters can be installed easily without any tools. HIGH-QUALITY LIFE - To keep your for Core 400S running at high performance, it is recommended to replace the Core 400S-RF filter every 6-8 months, also depending on your frequency of use.<br><br>NOTE: This is not an product. Any use of the name or model designation for this product is made solely for the purpose of demonstrating compatibility. Material: composite material colour: yellow<br><br>Package Contents: 2 x Replacement Filter<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.