These brewing lids work perfectly to cover brewing water kefir in standard wide mouth mason jars. The mesh is tight enough to keep out ants, dust, and debris while letting air flow out. I had been using coffee filters secured with a rubber band. These lids are faster, easier, look more tidy, and don’t use up your coffee filters. The instructions had a note about not tightening them too tight (might be hard to remove if you do.) There doesn’t seem to be any reason to crank them down tight. They’ll do their job screwed on loosely. The screw on portion has indents to allow you to get a good grip on them. It’s nice that they come in a pack of two, so you’ll always have a clean one available.

I'm truly appreciative of this product that's it and was made and available.