Perfect for helping to keep food fresh in nearly any resealable glass jar, including all mason jars. The Food Saver jar sealers are limited to mason jars with the two-part canning lids that can be hard to remove. With my pvc vacuum chamber and your vacuum sealer with an accessory port and hose (sealer and hose are NOT included), you can seal nearly any glass container. Reuse spaghetti sauce jars - just put the lid on on with a very light twist, put the top of the pvc chamber on, insert the hose and suck out the air. It'll create a vacuum seal in the jar! If it does not, back off on the twist as if the lid is on too tight, the vacuum sealer won't be able to remove the air from the jar inside the chamber. In the Small Chamber, measuring 8" x 4", two 1/2 pint jars can be vacuum sealed at the same time. Any jar less than 4" in diameter and up to 8" tall will fit. In the Medium Chamber, measuring 10.5" x 4", two pint jars will fit or one quart jar. The chamber is ideally used with a Food Saver vacuum sealer that has a hose attachment. If your model has a hose port, but no hose, you'll need to order a hose elsewhere. Amazon and eBay both have them. The food saver is NOT included. If you don't have a vacuum sealer, you can also use the vacuum chamber with a brake bleeder, which can be purchased for around $20-$25 from Amazon.