Fantastic for mason jars despite Vevor's answered questions saying it can't. Even handles the half gallon / 2L jars. Nice to be able to do many small jars at once.
Only feature sorely missing is a "Seal only" feature, as often I like to simply seal goods that don't need a vacuum or would be crushed by a vacuum, or seal bags cut from a roll. Can do it by setting depressurising time very low, but it's a hassle.
And unlike some other models, you can't seal very long bags which sit outside the machine with just their lip just sitting inside.
Cleaning - awkward if the low pressure causes a liquid to boil at ambient temperature and spill around the seal bar - so best watch, cancel and reduce depressurising time.