Package Included: 2 Pack 200/300 series Post Filter Replacement Dimensions: 17.9 inch * 14.4 inch Compatible with Blueair 200 & 300 series Models: Compatible For Blueair classic 200, Compatible For Blueair classic 201, Compatible For Blueair classic 203, 203C, Compatible For Blueair classic 205, 205C, Compatible For Blueair classic 210, 210B, Compatible For Blueair classic 215, 215B, Compatible For Blueair classic 250, 250E, Compatible For Blueair classic 270, 270E, Compatible For Blueair classic 303 Suitable Occasions: This blueair 203 replacement filter is suitable for living room, bedroom, kitchen, and office. It can greatly improve air quality, reducing unpleasant odors from pets, smoke, cooking fumes, and various household products and chemicals. Replace Regularly: For optimum performance, We recommend you to replace the hepa filter every 6-12 months and pre-filter every 2-3 months or depending the air quality and usage frequency. Kindly Note: This is not a OEM product and is not covered under any OEM manufacturer's promise. Any use of OEM brand name or model designation for this product is made solely for purposes of demonstrating compatibility.