This commonly used incubation medium is highly absorbent, inert and long lasting. This is Size 1 Ultra Fine grade Vermiculite. It is particularly suited to phasmid and katydid egg incubation as it can be sieved easily to separate eggs from medium. It is also suitable for reptile egg incubation, moisture retention in invertebrate enclosures and water retention in invertebrate browse containers. Sold per 3 litres which is approximately  500 g by weight.