Biomed Solutions Mushroom Grow Bag Cap and Ring for Cultivating Sealing Cotton Filter Cover 40mm(Pack of 9)

You can reinforce the filter with another layer of porous tape + loosely placed aluminum foil (for breathing), but they do the job of keeping the contaminants out while providing safe and easy access for inoculation.

The sleeves work really well. Some people have said they don't secure well at all but I don't think they are actually clicking the 2 pieces closed. They are very difficult to pry apart once you close them. Only downside is the cheap foam filter on top. I added some micropore tape on top of the filter and it works fine.

I wasn't really impressed with the quality of this product. I'm fairly new to mushroom cultivation so I was really excited to try these rings out but when I got them they were subpar in my opinion. They are super small and flimsy I'm not even sure what the filter is made out of and there were no instructions whatsoever. Save your money for some better options that are out there.

I haven’t yet got to PC these….but I will say that they are nice and thick…….they feel super solid. Exactly what I wanted for the tek I’d like to try.

It came well packaged in a thick resealable bag. We love mushrooms and eat them every day in a variety of different meals, so my husband has been really excited for us to start growing them ourselves. We started by saving our coffee grounds for a few weeks to use as a growing medium, in anticipation of growing some mushrooms. Then we had to buy some bags to get started, and saw these, not realizing that these are just caps that come in this kit. I know it’s clear in the listing but, what can I say, I am not very observant sometimes. Anyway, after pasteurizing the grounds and adding sawdust (the coffee grounds can compact too much otherwise) the mixture is ready to add culture. We have 6 mil bags that are 20" x 8" x 5”. The cap was a little challenging to fit on, I think due to the thickness of the bag, but stayed in place fairly well once attached. At this time, it’s too early to tell how well it works but I am very excited and optimistic. If it works the way I expect, then this will make a huge difference for us. Growing your own food has a lot of advantages, you know where it came from, you know that nothing has been added to it, I think it’s generally healthier, and you have a profound feeling of accomplishment. And for us, we won't have "we need more mushrooms" as a reason to have to run to town. All in all, I would definitely recommend.