These Harris Coconut Coir Piths, made of coconut fiber, are extracted from the outer husk of coconut. Use coconut coir as an additive to your soil or potting mixes to distribute nutrients uniformly and allow the roots of the plant to grow thick and healthy. The pack includes 4 bricks, each measuring 8 in. x 4 in. x 2 in., and expanding to approximately 9 qt. once hydrated (at least 8x its original size).