21 1/2" x 23 1/2" x 1" MERV 4 - Residential Washable Air Filter Residential Washable Air Filter:21 1/2" x 23 1/2" x 1" MERV 4 - Residential Washable Air Filter 12" x 12" x 1"

12" x 12" x 1" MERV 6 - Fiberglass Air Filter - 6 Pack

you may need to change your filter more frequently than once a month

24" x 24" x 2" Permanent Washable Air Filter - 1 Pack

Factory made to fit with no hassles or problems cutting and sizing adjustable filters

Actual Dimensions: 14 1/2" x 24 1/2" x 3/4"

21 1/2" x 23 1/2" x 1" MERV 4 - Residential Washable Air Filter Residential Washable Air Filter:21 1/2" x 23 1/2" x 1" MERV 4 - Residential Washable Air Filter 12" x 12" x 1"21 1 2" x 23 1 2" x 1" MERV 4 Residential Washable Air Filter 1 Pack Actual Dimensions: 21. 5" x 23. 5" x 3 4 These quality filters are built to last a lifetime. They are interchangeable with 1" disposable filters and can be used again and again. The secret behind the filter's performance is its patented stage loading peak and valley design. Instead of face loading (particles captured on the outer surface of the filter) the filter uses stage loading,