Vac& Stack Mason jar Vac Lids 5-Pk (Wide Mouth with Pump) Completely BPA-Free, Food-Safe & Dishwasher Safe  Reliably vacuum-pack Mason jars for months Low-profile Check Valve lets you stack jars atop one another One-piece reusable Aluminum Mason jar Vac Lids with Sealing Band bonded to Lid (no assembly or disassembly required) Works without metal collar, making it easier and quicker to close & reenter jars Five Wide Mouth (3.37-inch Diameter) Vac&Stack Mason jar Vac Lids & Pump