Our Foam Filter rolls are manufactured in the USA and has the following specifications:1/4 inch thick24 inches wide25 feet longMERV 4 rating30 Pores per square inch (trade spec)Polyether foamDark Gray / Black colorInitial Resistance 0.15 In. WC, Final Resistance 0.50 In. WC 5W913 Need a LOT of foam or other sizes / Types? Contact us for special pricing.