Uni Air Filter BF-6 Foam Sheet Uni Air Filter Universal Foam for you to fabricate your own design! Sheet Size 12 X 16 X 5/8 - 60 PPI Red Coarse Foam bonded to 60 PPI Yellow Fine Foam.Please see our Warranty & Returns Policy. Item Number: BF-6 Foam Piece: 16" x 12" and is 5/8 Inch Thick 40 PPI Red - Coarse / 60 PPI Yellow - Fine (pores per inch) Easy To Use: Place your existing filter on top of foam, trace it out, and then cut it out with scissors Made in U.S.A.