This vacuum chamber is perfect to use in sealing not only Mason Jars for food preservation, but also pickle jars, Salsa jars or others with a sealing lid. I just put the closed jar into the chamber, pull a vacuum, and then release. The lid will pull down sealing the contents in an air tight vacuum to help keep my dehydrated foods safe. This saves me money by allowing me to reuse my condiment jars and not throwing them into the land fill.