6Pcs Wide Mouth Mushroom Liquid Culture Lid Grain Spawn Cultivation Mason Jar Lid with 0.2 micron PTFE Syringe Filter & 20mm Self Healing Injection Ports For Mushroom Growing Mycology(Silver)

good fit no plastic.

4 of the six lids will not screw on or fit

They do the trick (see my photos) and work on both my Ball and Kerr wide-mouth jars. Good enough air/gas exchange for my mycelium on agar.

The mushroom lids I recieved were made of great quality and the customer service is helpful with any questions. I highly recommend this product.

Some of them fit, some of them don’t. A defect in manufacturing that needs to be looked at.... (The threads on the lids are inconsistent). To the seller, I would recommend I guess that you should look at each one of them before you ship. 😬 thanks-Update: It wasn’t so bad, as five out of the six did fit. (Just one bad one in my package). The vendor sent me a very nice email, and let me know that they have updated their moulds (fixing the issue, per the email). They offered to send me the new ones for free replacement. I’m happy to hear that they confirmed the issue and fixed the moulds.

IDK if I got lucky or what but they all fit my kerr and ball jars perfectly. No problems here.

They fit perfectly on my off brand quart jars but do not fit on my ball piny jars. I tried 6 different lids on different jars and they don't fit at all.

These jar lids are a solid product. After opening the box, I was pleased to see each lid sealed within its own plastic bag. Within each bag, you'll find the jar lid with the self healing port already in place. The plastic filter-disk assembly is also in this bag and simply needs to be inserted into plastic hole in the top which acts as a conduit between the inside and outside of the jar. These fit the jars very snugly and handle being pressure cooked without any issue.I have noticed that the plastic nut on the underside of the lid which holds the conduit for the filter disk can be a little bit loose, but a simple check and hand-tightening of the nut ensures the conduit into the jar is tightly secured and snug against the lid of the jar. I don't think this is a flaw with the product--it's not unreasonable for a plastic nut to slightly loosen during the shipping/stocking process.My only reasons for not giving 5 stars:1) Some of the injection ports seem to not sit fully flush with the top. However, their shape allows them to still maintain their seal so this really seems to be more of an aesthetic issue rather than a functional issue--not really a reason to give a full 5 stars.2) After pressure cooking with the filter disks installed, I find that they aren't quite as snug as they were prior to sterilization--much easier to pull out of their port, but not loose--the seal is maintained so long as you don't try pull them out.The second issue is more concerning; however, it shouldn't be a problem for anyone exercising care with the issue in mind.Overall they are a very solid product. I enjoy mycology as a hobby and I've found that they have worked very well in my experiments with cloning wild oyster mushrooms and Agaricus species. I have liquid cultures that have lasted months without any contamination making its way in from the outside, so they absolutely do their job quite well. I would buy them again if I needed more!