You are looking at a lot of 12 synthetic filter discs used for mushroom cultivation. These discs are widely used by commercial producers, as well as those involved in smaller home cultivation. These synthetic filters discs fit precisely on any wide mouth 90mm canning jar which are commonly used by today's cultivators. Usage of these discs allows a fresh, constant air exchange while preventing the entrance of unwanted contaminates. Use them in place of jar lids, or just drill a hole in the lid, and place the discs under the lid.

Our synthetic filter discs can be used within a pressure cooker, steam sterilizer or autoclave. They are reusable, highly durable and have a filtration rate of 99.97% that means they will filter down to .3 microns. They come in 90mm sizes but they are all a true 1/16 of an inch thick! This equals to roughly 13 sheets of filter paper.