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Need a different depth?

Same size, deeper filter

Below is 17x21 at 1 naturalaire″. A thicker filter holds more before it loads up, so it lasts longer between changes and puts less strain on the blower — we carry the same width and height in the depths below.

17x21x2 Built to order 17x21x4 Built to order

Ordering for a building? Ask for volume pricing or call 1-866-469-8556.

  • 17x21x1 NaturalAire Standard MERV 8 Filters (12 pack)
    MERV 8
    AAF Flanders

    17x21x1 NaturalAire Standard MERV 8

    $168.99
    $168.99
    Case of 12 $14.08/filter
  • 17x21x1 NaturalAire Standard MERV 8 Filters (12 pack)
    MERV 8Up to $49.11 offContact Support
    AAF Flanders

    WAREHOUSE DEAL 17x21x1 NaturalAire Standard MERV 8

    $104.88
    $104.88 $153.99
    Case of 12 $8.74/filter
  • 17x21x1 Flanders EZ Flow Fiberglass MERV 1-4 Filter 10055.011721 (12 Filters)
    MERV 1-4
    AAF Flanders

    17x21x1 Flanders EZ Flow Fiberglass MERV 1-4 Filter

    $101.99
    $101.99
    Case of 12 $8.50/filter
  • 21x21x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    MERV 13
    AAF Flanders

    21x21x1 NaturalAire Healthy Ultra MERV 13

    $257.99
    $257.99
    Case of 12 $21.50/filter
  • NaturalAire Standard MERV 8 (12 Filters)
    MERV 8
    AAF Flanders

    NaturalAire Standard MERV 8

    From $95.99
    From $95.99
    Case of 12 $8.00/filter
  • 21x21x1 NaturalAire Standard MERV 8 84858.012121 (12 Filters)
    MERV 8
    AAF Flanders

    21x21x1 NaturalAire Standard MERV 8

    $175.99
    $175.99
    Case of 12 $14.67/filter
  • 17x29x1 NaturalAire Microparticle MERV 10 Filters (12 pack)
    MERV 10
    AAF Flanders

    17x29x1 NaturalAire Microparticle MERV 10

    $120.99
    $120.99
    Case of 6 $20.17/filter
  • 17x29x1 NaturalAire Healthy Ultra MERV 13 Filters (12 pack)
    AAF Flanders

    17x29x1 NaturalAire Healthy Ultra MERV 13

    $359.99
    $359.99
    Case of 12 $30.00/filter
  • 17x29x1 NaturalAire Standard MERV 8 Filters (12 pack)
    AAF Flanders

    17x29x1 NaturalAire Standard MERV 8

    $276.99
    $276.99
    Case of 12 $23.08/filter
  • 17x21x1 Exact Filters Pleated MERV 11 (12 pack)
    MERV 11
    Exact Filters

    17x21x1 Pleated MERV 11

    $247.99
    $247.99
    Case of 12 $20.67/filter
  • 17x21x1 Exact Filters Pleated MERV 13 (12 pack)
    MERV 13
    Exact Filters

    17x21x1 Pleated MERV 13

    $268.99
    $268.99
    Case of 12 $22.42/filter
  • 17x21x1 Exact Filters Fiberglass MERV 1-4 (12 pack)
    MERV 1-4
    Exact Filters

    17x21x1 Fiberglass MERV 1-4

    $174.99
    $174.99
    Case of 12 $14.58/filter