Anonymous wrote:It's to get an air tight seal when canning, you don't need to use it if you just storing dry food.
Anonymous wrote:I got two glass jars and both came with a rubber thing. Mine is white, but it looks like this: https://www.amazon.com/Kilner-0025-501-Replacement-Seals-3L/dp/B019E21EEU/ref=asc_df_B019E21EEU/?tag=hyprod-20&linkCode=df0&hvadid=652411026717&hvpos=&hvnetw=g&hvrand=17813295699550729299&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1014221&hvtargid=pla-600085385452&mcid=28658868f62131d6a22d95d395e84b9b&th=1
How do I use it? What's it for? Do I need to use it? It makes it harder to fasten the jar.