![Blueair Diagram showing which air purifier model should be used for the filter Blueair Diagram showing which air purifier model should be used for the filter](https://www.blueair.com/dw/image/v2/AASF_PRD/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw7dfac1fa/2024%20-%20Filter%20PDPs/Inside311i+Max.png?sw=468)
Designed specifically for the Blue Pure 311i+ Max.
Find the name of your air purifier on the label inside your air purifier.
![Blueair Blueair AllergenBlock reduces exposure to allergens Blueair Blueair AllergenBlock reduces exposure to allergens](https://www.blueair.com/dw/image/v2/AASF_PRD/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw62dcf2a3/2024%20-%20Filter%20PDPs/AllergenBlock%20Tech.png?sw=468)
against allergens
Blueair’s AllergenBlock¹ technology reduces your exposure to pollen, pet dander, and dust allergens, by neutralizing over 90%² of their sneeze-inducing properties once caught on the filter.
![Blueair Main filter Blueair Main filter](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dwce86c25c/2024%20-%20Filter%20PDPs/AllergenBlock-Filter.png)
Captures airborne particles, including pollen, dust, and pet dander allergens.
![Blueair AllergenBlock defense Blueair AllergenBlock defense](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw8ce63656/2024%20-%20Filter%20PDPs/Allergen.png)
Neutralizes² over 90% of the allergen properties that can trigger discomfort.
![Blueair Activated carbon Blueair Activated carbon](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw7ea5499f/2024%20-%20Filter%20PDPs/Carbon.png)
Traps light household odors from pets, cooking and smoking
![Blueair Blueair RealTrack Technology Blueair Blueair RealTrack Technology](https://www.blueair.com/dw/image/v2/AASF_PRD/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw53ef500d/2024%20-%20Filter%20PDPs/F3MAX+.png?sw=468)
lifetime status
Only Blueair air purifiers use HEPASilent™ dual filtration technology for maximum filtration and minimum noise.
![Blueair Blueair genuine filter Blueair Blueair genuine filter](https://www.blueair.com/dw/image/v2/AASF_PRD/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw36818865/2024%20-%20Filter%20PDPs/Genuine%20Filter.png?sw=468)
replacement filter
Protect your air purifier from damage
caused by unofficial filters.
![Blueair Image Blueair Image](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw00ec6c28/2023%20Icons/Icon_Bacteria.png)
With the unique filter design at least 99.97%³ of airborne particles, even down to 0.1 microns, are removed, while using less energy and producing less noise.
![Blueair Works 24/7, for six months straight Blueair Works 24/7, for six months straight](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw3ef1dc59/New/Icons/icon_onebutton.png)
To maintain optimal performance, we recommend changing your filter about once every 6-months when used 24 hours a day. Don't forget to save with our subscription program.
![Blueair Keeps clean air flowing, resists clogging Blueair Keeps clean air flowing, resists clogging](https://www.blueair.com/on/demandware.static/-/Library-Sites-blueair-ca-content-library/default/dw478ffea1/2023%20Icons/Icon_Dust.png)
This filter's unique structure is designed to filter high volumes of air while trapping even the smallest particles. It maintains maximum airflow because it's engineered to resist clogging.
-
Dimensions(HxWxD)11.4 x 7.9 x 2.5 in in
-
Product weight0.5lbs
-
Recommended filter change6 months (4,380 hours) when used 24 hours a day
-
Number of filters1
![F3MAX+ AllergenBlock Replacement Filter for 311i+ Max F3MAX+ AllergenBlock Replacement Filter for 311i+ Max](https://www.blueair.com/dw/image/v2/AASF_PRD/on/demandware.static/-/Sites-blueair-master-catalog/default/dwd115443a/filters/blue/Max/Replacement%20Max/AllergenBlock/311i+.png?sw=450&sh=450&sm=fit)
This filter is compatible with the Blue Pure 311i+ Max air purifier.
Purchasing a filter subscription saves you 15% on all future replacement filter orders + free shipping. At the time of purchase, the subscription will automatically schedule filter deliveries at the recommended six months. You can always adjust this timeframe from the 'My Account' section.
¹ AllergenBlock refers to inanimate allergens pollen, dust and pet dander.
² Based on ELISA deactivation testing of Pollen (Cry J1), Pet Dander (Fel d1, Can F1), Dust Mite Matter (Der f1) on the filter media in 60 minutes.
³ A flat shipping rate of $25.00 will be charged on filter shipments to Alaska, Hawaii, and Puerto Rico. Additional charges may apply for shipments over 30 lbs. A flat shipping rate of $5 will be charged on orders under $39 that are not part of filter subscription.