Made from 100% natural coconut fibre. This bedding block will expand up to 10 times its original size once water is added. This creates the ideal bedding / environment to start up your worm farm. Our coconut fibre contains no nasty chemicals or salts. This coir fibre bedding block can also be used an addition to potting mixes or soil mixes for moisture retention in pot plants, garden beds, vertical gardens & planter boxes.