SUCOHANS 100 peices Mushrooms Self Healing Injection Ports, 20mm Rubber Bottle Stoppers, for 13 mm (0.51in) Diameter Opening Mason Jar Lids

Great self healing.

Clean with rubbing alcohol, then use gloved hands to press into place. Start one end, push in, fold grommet until aligned then press into place all around.Clean top again before use. Use drill for lid top for the best fitment. Be careful to not slip and cut yourself on drill hole. Remember, you can make your hole bigger but never smaller, the whole point is for a sealed system ; )

These are exactly what I needed along with the gas exchange ports I purchased to craft my own lids for my LC & grain jars.

Sturdy and easy to use.

Worked well for anyone else wondering these work well with the plastic lids use a 29 / 64 (11.5 mm) drill bit for snug application obviously still not as good as drmyc ports but the price was right end work well for what I needed them for

Quality of item is as described

As Advertised

I was using RTV Silicone for my liquid culture before, but recently the needle actually pulled out the plug, and contaminated the culture :( So I ended up springing for these. They don't have a notch on the backside like I hoped, so they don't look like they would hold in place. But after drilling a 1/2" hole, pushing it through, it did expand on the other side, and seems to be snug enough to not pull out with the needle. + much nicer looking than the RTV (and easier to find where the needle goes). I'll update if it does end up pulling out, but so far so good!