***It is made of non-woven polypropylene with PTFE,which has been used as filter patches for mushroom growing bags for a long time.***

***0.2 micron filter means it has a filtration rate of 99.98%***

***These filters are one of the best choices for your mushroom cultivation, especially for long term incubation projects. as a nature of the material, those filters can be used within a pressure cooker, steam sterilizer or autoclave. they are reusable and highly durable.***

***The filters are thin, you can very easily adapt them to other sizes and containers.***

When you stick the filter paper to other surface with glue, please make sure apply glue only on the PTFE membrane side, which you feel smoother than the other side.