Nordic Pure 17x21x1ExactCustomM8-6 MERV 8 AC Furnace Filters, 6 Piece Actual Size: 17 x 21 x 3/4 Exact (17x21x0.75) This item is made to the exact size listed above. Please measure your current filter and compare sizes before you order MERV 8 media is ideal for normal air filtration and will help those with mild allergies Hypoallergenic and antimicrobial pleated electrostatic filter material Made in the USA