Washable Electrostatic Antimicrobial Furnace Filter Our filter replaces your disposable Pleated filters. Stop throwing your cash in the trash.Our filter works by generating a static charge as air passes over it. No electricity is needed. Simply vacuum off the filter (optional step) wash this filter out, being sure to back wash the filter in the opposite direction of airflow, there is label on the filter indicating this. Allow to air Dry, and reinstall. We do not recommend the use of High-pressure water or air, don't use a pressure washer or air compressor, or leaf blower on it. We do not warrant the filter for improper cleaning techniques. A mild detergent such as Dawn® or Simple Green ® may be used if you like but is not necessary. We recommend you wash it every 60 - 90 days, this will vary based on many variables in your home.Homes with pets may require more frequent washing. Upon initial installation we recommend checking it every 30 days until you determine the best washing cycle for your home. Every home is different so it is difficult for us to prescribe a specific washing schedule for application. Helps Capture Dust, Pollen, Pet Hair, Pet Dander, and Other AllergensAntimicrobial materials to help inhibit bacteria growth.Heavy Duty Aluminum FrameDrain holes for faster dryingImpact resistantLong Lasting MERV 9 Rated Please note all sizes listed are Nominal filter sizes. Except for "EXACT SIZE" filters which are not undercut like nominal filters are. All filters are 3/8" smaller in length and width than listed size.Example: a 16 x 25 filter actually measures 15-5/8 x 24-5/8 this is an industry standard.All filters are nominal 1" thick, actual thickness is 7/8" please check your clearances to be sure it will fit before ordering. We have 59 sizes listed plus two Custom size options.We can get you any filter, any size. Ships via most economical ground service. For Custom Sizes:First multiply the Width x length of the filter you need. Example: 21-1/2 x 27-3/4" = 467.625 square inchesIf the custom size you need is 500 square inches or under, order " Custom Size under 500 square inches"If the filter you need is more than 500 square inches order "Custom Size over 500 square inches"when you order, include the EXACT dimensions of the filter you need. The filter will be made to your exact dimensions. You may also just message us with the exact dimensions after you place the order. Buy with peace of mind, we have been on eBay for over 25 years. Manufactured In the United States of America with Domestic Raw Materials and Labor