High quality blend of natural sand, coconut fiber, sea salt and probiotics which accurately replicate the optimal natural environment for hermit crabs. Having the proper substrate is essential, as hermit crabs are natural diggers they search for food and nutrients between the grains, and they also need moist sand to stay hydrated and aid in the molting process. The added calcium and sea salt help mimic the natural sea environment and probiotics help maintain a cleaner, healthier environment.