This 1" thick foam is true "fish-grade," long-life, reticulated foam with a pore size of 20 ppi (pores per inch). It contains no fire retardants or germicides (be careful with low-cost air filter foam—it can be toxic!). Sold in 2' x 6' sheets (rolled) only (equals 1 cu.ft.). Weighs 5 lbs. Large quantities can be shipped flat.