Mason Jar Lifestyle Platinum Silicone Sealing Gaskets for Leak Proof Lids | 10 Pcs Reusable Seal Rings Replacement for Plastic Lids (Regular Mouth)

They fit my jars perfectly.

I had a few cheap new mason jars and as I was washing them I noticed that water leaked out. I needed them to be airtight for storage, but no matter how tight the lids were they leaked water. These silicone rings matched the size of the jars and fit tightly inside the lids. When the lids are on tight no water leaks out with these rings in place and I assume that the jars are now airtight. Very good item and worked well for my situation.

The rings I received are about 1.5mm thick with no groove on either side. When used with the green Ball brand plastic lids I find they are difficult to seat properly without looking through the jar at the rim to ensure they stay put which is extremely difficult with food that is not clear. If seated properly they make an excellent air tight seal.

I needed a decent gasket to seal my Mason jars while I degas the contents under vacuum. These do the job magnificently!

I was hoping these would fit on my empty spaghetti sauce mason jars. They do... no issues what-so-ever. Perfect... now I don’t have to go buy expensive mason jars.