You are purchasing on 10 Spawn Bags! These are the best in the business. An autoclavable spawn incubation bag with a micro-porous filter patch that allows gas exchange but prevents the passage of contaminants. Spawn bags are an economical substitute to canning jars. When producing bulk amounts of substrate, spawn bags are able to hold larger amounts of rye grain, seed, or any substrate that you may be using. material : polypropylene purpose: for spawn number of filter strips front: 1 number of filter strips back: 1 bottom gusset: (2 total) yes heat resistance: 124°C - 255 °F width : 7.4 inch height: 12.6 inch