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    Ruud 21x21x4.5 - RXFH-E21AM10, RXFH-E21AM13

    Actual Size: 20.75x20.75x4.38"

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    3 month filters

    1. Select Performance Level

    2. Select Quantity

    6 Ruud 21x21x4.5 - RXFH-E21AM10, RXFH-E21AM13 for $31.70 each
    Quantity Discount
    1 for$56.01 ea2 for$35.00 eaSave 38%3 for$33.67 eaSave 40%4 for$32.36 eaSave 42%5 for$32.03 eaSave 43%6+ for$31.70 eaSave 43%

    3. Select Delivery Method

    $190.20
    $336.06

    You will still be able to review your order details.

    USA

    Made in the USA

    Ships in 24 Hours

    Ruud 21x21x4.5 - RXFH-E21AM10, RXFH-E21AM13 Air Filter Description

    • Available In MERV Rating: 8, 11, 13

    • Made in the USA

    • Ships in 24 hours

    Merv comparison

    Scroll to see more.

    MERV 8

    MERV 8

    MERV 11

    MERV 11

    MERV 13

    MERV 13

    Best for

    Standard

    Residential/Commercial

    Healthy Families

    Superior

    Residential/Commercial

    Allergy Sufferers

    Optimal

    Residential/Commercial

    Hospital Grade

    Comparible ratingsMPR 600 & FPR 5MPR 1000-1200 & FPR 7MPR 1500 - 1900 & FPR 10
    Filtration

    Captures 90% of Airborne Particles

    Captures 95% of Airborne Particles

    Captures 98% of Airborne Particles

    Dust, lint & debris
    Mold, pollen
    Dander, dust mites
    Smoke & smog
    Bacteria
    Odor, vocs

    Is it time to change your filter?

    Generally, we recommend you replace your air filters every 90 days. Find out below if you should change your filters more often.

    If someone in your home has asthma or allergies...

    If someone in your home has asthma or allergies...

    Change your filter every

    6 weeks

    to ensure indoor air quality is at its best.

    If you have pets...

    If you have pets...

    Change your filter every

    2 months

    to avoid shedding and odor buildup.

    If you have young children...

    If you have young children...

    Change your filter every

    2-3 months

    as having clean air is even more important with children in your home.

    Reviews From Satisfied Customers

    5star

    So glad to finally find the right size filter I needed. Ordered some online before and didn't fit right. Even my AC company didn't have the right size either. Told my daughter about your company, as she just got a whole house AC replaced. Shipping was super fast too. Sharon

    Sharon s.

    Verifiedverified buyer
    5star

    I recently had to order a large box filter for my HVAC system but I did not recall the size. I called Filter Buy and provided my name and shipping address. The prior order was quickly retrieved and I placed my order, which arrived very quickly. This is a top notch company with top notch products.

    John W.

    Verifiedverified buyer
    5star

    The cost was not bad,it's always a good quality and perfect size

    Kathleen N.

    Verifiedverified buyer