Plastic Lids for Wide-Mouth Jars
Product Review (submitted on February 24, 2014):
No more annoying 2-part lids for mason jars - these lids are exactly what people who use canning jars for fermenting need!
Very handy, good price; I got a box of each of the large and small lids, and they're all in use. :)
As mentioned before, the lids are not reliably water-tight, which means they're also not air-tight - so they don't work as well for the actual fermenting process as the 2-part canning lids, but for fridge storage of my fermented veggies and kefirs they're exactly what I need.