This Set is Designed for Wide Mouth Vacuum Sealing Mason Jars with PURE's Plain Lids (no valve).  What's Included? MVP Pump PSA Wide Mouth Adapter Lid Key  Owners’ Manual The Components! The MVP Pump is the very best portable pump for vacuum sealing juice and dry goods.The MVP pump removes more oxygen 80-85% (80-85kPa) than any other pump on the market. Most pumps remove 20%-65% oxygen and are built to throw-away standards. Not so with the MVP Pump no expense was spared. In a good-better-best world, PURE chose best with every pump component from the aerospace aluminum body, the stainless steel pushrod through the all-metal leaf handle the MVP Pump exudes quality.  The PSA Adapter is the Best Adapter on the Market Mason jars are not all the same, there is a lot of size variation on the critical sealing surface. This is the failure point and why most other systems are disappointing.  PURE designed the PSA Adapter to fit the widest variety of mason jars possible. This means better sealing to more jars at the highest possible vacuum Lid Key, Because the MVP Pump pulls so much vacuum, a lid key is needed to remove the lid Cleaning,Hand wash with warm soapy water (not dishwasher safe).MVP Owners Manual, https://cdn.shopify.com/s/files/1/0111/7369/1473/files/PURE_MVP_InstructionManual-2024_11_02_Rev6.5.pdf?v=1734125274