Aprilaire 401 Deep Pleated Media Filter for Model 2400
4824 - Aprilaire 4824 - Plastic Door with Seal (Grey)
Amazon.com: Aprilaire / Space-Gard 401 High Efficiency Filtering Media - 2 PK : Home & Kitchen
Amazon.com: WKZO 401 Replacement Air Filter for Aprilaire Model 2400, GeneralAire Model AC24, Source1 Model S1-MAC11162506, (Pack of 1) : Home & Kitchen