4 Pickle Pusher Small Batch Fermentation Kits. Complete with Airlock and Weight-Replacement. BPA Free. Holds 25X More Than Fermenting Weights. Fits Widemouth Mason Jars Not Included

These take the place of cabbage leaves and weights to hold down the ferment in your Mason jars. They work really good, and stay in place. The air-locks (with water) allow gases to escape, but keep air (and mold spores) from going into the ferment. I have 4 jars of sauerkraut I fermented in wide-mouth Mason jars for four weeks using this system. No mold at all!!! The silicone plunger kept all the vegetables below the brine. We have very tasty and probiotic-rich sauerkraut in our refrigerator now. These are a must-have for jar fermenting, better than any other system out there (I know, I've tried them all).