We have tested our product to hold a vacuum for a full year. All shipped products are tested to hold a vacuum for at minimum one week. As soon as a unit is made it is put under vacuum and the vacuum is released before packaging and shipping.
The rechargeable is not as strong as the Pro-Vac but it does pull a -20hg vacuum in approximately 15 seconds on a 1oz jar (500ml). For comparison, the Pro-Vac will pull -25 to -28hg in 3 seconds. Both examples are with empty jars. Obviously, the more volume of contents inside the jar will decrease the time to pull a vacuum.
Due to the fact we are shipping glass, the products are packaged in boxes that are large enough to allow sufficient packaging material to protect the items. We make no profit from shipping. All charges directly from the USPS and are calculated by size, weight and your zip code. We ship from Orange County, California.
Simply remove the rubber O-ring (gasket) and rinse with warm water. Wipe down the glass areas where the O-ring comes in contact before replacing the O-ring. Small debris can cause a slow air leak over time.