Eco Earth is made of an environmentally friendly, entirely renewable coconut fiber. Just place the compressed brick into a bucket or sink, add 4 quarts of water and in 20-30 minutes, you'll have 7-8 liters of substrate that can be used damp, or dried in the sun depending on the type of habitat in which it's used. Eco Earth naturally absorbs and breaks down odor and waste products and can be safely composted or recycled after use. This is a special value pack, 3 bricks for the price of two.