64Pcs 20mm Diameter Synthetic Filter disc Hydrophobic PTFE Membrane 0.3um Pore Size Strong Adhesive for Mushroom Cultivation

Great for making your own home made spawn jars! They stayed on after sterilization!

Worked great for my project.

I love these! Very easy to use, made it through the pressure cooker at least 3 times so far, and still look good as new. I have made at least 20 mushroom jars with no contamination. Will be a repeat consumer of these.

I used these to filter some gas exchange ports in a high humidity environment and they are doing a great job. There is a noticeable amount of gas and humidity exchange in an a radius around each filter. The adhesive is strong and bonded well with plastic. There is a circle cutout on the throw away backing that is probably useful for sanitizing the “clean side” of the filter prior to application, otherwise I don’t know why they’d go through the trouble to cut holes in it.

Excellent

Purchased these to modify some grow tubs. The smaller ones work best for my tubs.If using the larger patches, less is more. Tried using 4 of the larger patches and it allows too much gas exchange and it's hard to keep humidity.

this is a good product after further investigation I discovered that all of the patches were there I initiated a return but would like to cancel that now thanks and sorry about the confusion

work good but have since moved on to a different method