21 1/2" x 21 1/2" x 1" MERV 4 - Residential Washable Air Filter Residential Washable Air Filter:21 1/2" x 21 1/2" x 1" MERV 4 - Residential Washable Air Filter 24" x 25" x 1"

24" x 25" x 1" MERV 4 - Residential Washable Air Filter - 1 Pack

Never have to hassle with disposable filters that will end up in a landfill

Actual Dimensions: 9 7/8" x 17 7/8" x 3/4"

Actual Dimensions: 18" x 18" x 1 3/4

14" x 20" x 1" MERV 4 - Residential Washable Air Filter - 1 Pack

21 1/2" x 21 1/2" x 1" MERV 4 - Residential Washable Air Filter Residential Washable Air Filter:21 1/2" x 21 1/2" x 1" MERV 4 - Residential Washable Air Filter 24" x 25" x 1"21 1 2" x 21 1 2" x 1" MERV 4 Residential Washable Air Filter 1 Pack Actual Dimensions: 21. 5" x 21. 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,