Impressed by this little device. Sealed up 11 jars , still lots of battery use left. One thing I noticed was the inner black rubber-like ring that looks to be removable, sometimes pops out or not sitting in correct makes it quite hard to get the device off the jar after it's sealed. I push it back in an reform it to sit properly that helps.
That doesn't effect the sealing of the lid, just an inconvenience . I still love it. Nice size and effective. My cupboard looks way neater now.