This listing includes 2 Mushroom Substrate Bags in the size you want. (Coir and Vermiculite) (0.5 micron filter)
A 3T Bag will hold 3-4lbs of substrate
XLS Bags hold twice as much substrate as 3T, approximately 7 lbs.
These substrate bags can be used to cultivate your own mushrooms at home. Used bags last for months in storage.