When I decided to invent this product, I was trying to solve two common problems with Mason jar lids: either they leak (like the plastic Ball lids), or they are not food safe (like many decorative lids). These flat, round discs solve both problems! The food only comes in contact with the silicone, and they make many lids airtight and watertight.
They are made of clear, food grade, BPA free, platinum cured silicone rubber.
The regular mouth size are 70mm in diameter and 2.7mm thick.
The wide mouth size are 86.5mm in diameter and 3.3mm thick.
These lids fit in Ball plastic storage caps and will not fall out when you hold them upside down. Because silicone is a flexible material, they fit some other lids too, even if they are not the exact same size. But lids for Mason jars come in a wide variety of shapes and sizes, so these will not work with all of them. When possible we have tried to identify on our site which of our lids will work with these inserts. Note that with some types of lids they won’t look like they are fitting correctly, but when you tighten the lid they may still create a good seal. If they seem a little too big for your lid, you can trim them with a scissors. Silicone will not be harmed by cutting it and will retain all the same properties.
You can even use these liners with just a band / ring and they will not leak!
Some of the many uses for our silicone sealing lid liners:
Any odor will disappear after washing them or letting them air out in sunlight.