Box was opened but the item is new and unused. I’m selling bc I accidentally purchased the wrong size. 🤗 Blueair 411 Replacement Filter 💙 OEM Part Number 110672 BOOST ALLERGEN PROTECTION: AllergenBlock defense layer neutralizes over 90% of the allergen properties such as sneeze-inducing dust, pollen and pet dander that can trigger discomfort UPGRADE YOUR DEFENSES: Blue Pure 311 Auto Series AllergenBlock Blueair filter is designed for optimal performance; Compatible with 311 Auto air purifier SNEEZE-INDUCING ALLERGENS: Four layers of air purifier filtration; AllergenBlock defense layer neutralizes over 90% of pollen, dust and pet dander on the Blueair filter; Carbon layer reduces light household odors AUTOMATED FILTER REPLACEMENT: Subscribe and save up to 10% on auto-delivered filters when replacement is needed; When used 24 hours a day, your Blueair filter should be replaced every 6 months to effectively reduce airborne pollutants and allergens