Sunbeam SF212 OEM Cool Mist Humidifier Filter 'A', 2-pk Fits Holmes, Sunbeam, and Bionaire Humidifiers requiring Filter "A" Treated with Arm & Hammer Baking Soda for longer life Antimicrobial Treated Carbon X Treated Measures approximately 4" H x 4 1/2" ID x 6 1/2" OD x 1" Thick.