Packaging: 24pcs Regular Mouth Mason Jar Lids with Air Valve 24pcs Wide Mouth Mason Jar Lids with Air Valve 【Patented Design-Air Valve】 Our flat lids are equipped with One-way Air Valve, which improve air tightness and won’t bend.【Support Sealing by Electronic Vacuum Sealer and Boiling】 Compatible with ALL types of mason jar vacuum sealer.【Make Your Handheld Vacuum Sealer Multi-use】 If you have a Handheld Vacuum Sealer which works on reusable vacuum bags, you can also use it to seal Mason Jar with our sealing lids.【The Best Tool for DIY Fruit Canning and Preserving Food】 You can use it to seal marshmallows, cookies, jams, pickles, coffee beans, picnic foods.【Reusable Jar Lids】 Reusable regular mouth lids and wide mouth lids, 24pcs each.