There is a rubber ring inside the lid to make ...
585027
There is a rubber ring inside the lid to make it more tight connection to the jar, but the lid is still not watertight, because the lid opening itself does not have any rubber around it and if you shake the jar, the water will leak a bit. I don't think the cover is meant for storing liquids while laying on its side, anyway. The price is quite steep for only one jar cover, though.
4278383
I checked the reviews on another site and these canisters do have a rubber seal around the lids in case others were wondering the same thing.
2557839
Love the straw with rubber surrounding the straw holder. Doesn't slip off. The other lid didn't have this and now the straw falls of it. I would recommend this one!
4878450
I've used a new ring a few times now.  The size is a little off.  The outer diameter seems a bit big, but it's usable.  These new rings seem more like silicone than the original rubber gasket that came with the blender.  So I am not sure if these are the sealing rings that Oster makes now (since I bought my blender many years ago now) or if this is an "after market" gasket.  But they seem like they are going to last (hopefully).
867449
The lid has a gasket that keeps the water from leaking out, unfortunately, when you tighten the lid on, the friction causes the gasket to shift, thus making an imperfect seal.  It then leaks.
3751321
Lid will not stay on, even after using a rubber mallet.
2589468
This is an interesting device that is used to open European-style glass jars used for home preserving, like our Mason or Ball jars in the U.S.

Those jars usually have metal rings on lid and jar, with a hinge on one side and a clamp on the other.  However, sometimes only the glass jar and lid are used with a gasket.  How then to remove the lid?

This tool has wires that go around the jar in the gasket area and a large plastic wingnut on the end of the handle.  Tightening the nut tightens the wires and forces the lid to open, safely and so that it can be reused.

The tool is made of stainless steel with a plastic wingnut and is very durable.

Home Fashions provided a for evaluation and review.
495957
It does what it is supposed to, but the bottom ring isn't snug, so liquid could get caught in that ring.
1566810
The lid was bought for another pool that did not have it's own cover.  What I did not know, was that there are holes in the top that are big enough to let pieces of leaves and dirt inside.
1938149
there should be a non metallic knob on top of the lid. The metal knob gets too hot to touch.
211875
A good lid. I use it on my jars of milk in the fridge. (It is nice to be able to have a large container that is inexpensive and easy to clean in order to pour into baby bottles). It came through the dishwasher ok and has a great seal if you get the rubber ring correctly input. The reason why I gave it 4 stars instead of 5, is that the lid is extremely easy to open and easy to pull off the main part. I would have liked something a bit more sturdy and closer to the shaker bottle lids. It works well for my purposes and I'm thinking about trying to make sun tea with it and have the strings hang out the opening.
4625460
It's a rubber bucket, it acts like it should.
1072323
It's sufficient. Rubber ring is cheap and will move about but it's holding our coffee beans and I'm hoping it's keeping them fresh but we go through so many beans it's hard to say.
1161734
Lid doesn't close automatically. You must manually push it down.
4646460
The lid does not screw on all the way.  This is a poor design.
1740203
Nice construction,does what is supposed to do. Just needed an extra rubber ring.
1387556
The rubber part stays in the bottle. You have to carefully pull it out or you leave the ribbed rubber part behind. I would not buy this again and do not recommend it.