Humidifier Filter Replacement for Bionaire 900 (4-Pack) Aftermarket Product Sourced Exclusively by EFP - Exact Fit Parts High Quality Humidifier Wick Filter for Bionaire 900, 900cs, 900-cs Includes (4) Humidifier Filters as pictured Approximate Measurements: 9 x 7-1/4 x 2-5/8