Pickle Pebbles have been specifically designed for use with fermentation and take the guess work out of your lacto ferments by ensuring your veggies stay below the surface of the brine thereby eliminating exposure to oxygen (which is the main cause of failure when using lacto fermenting methods). Pickle Pebbles PLUS+ are designed for use in wide mouth canning jars, and can also be used in traditional ceramic crocks. With the Pickle Pebble PLUS+, one weight is often enough to keep veggies below the brine. Dimensions: 2.75" diameter with 0.75" thickness. Pickle Pebbles are made of non-iridized soda glass which is completely inert and guarantees that no other substances leach into your ferment.