Small Ceramic Fermentation Weight
Product Review (submitted on February 28, 2014):
I thought these might work based on the description but they are a little too small for half gallon wide mouth mason jars. Since they are zig zag in shape, you can fit them in the small mouthed jars. It did not cover the cabbage fully so I had to add my glass weights too.
I could fit three pieces in the half gallon jar. I will have to buy the large size to see how they will fit.