Serial nos.: DZ-400/2SA, DZ-400/2SB, DZ-500/2SB, DZ-500/2SC and DZ-600/2SA Ensuring that the lid of the vacuum case is pressed means the machine will automatically complete in an orderly manner the processes of vacuum extraction or aerating, sealing, printing, and cooling. The packaged products will be protected from oxidation, the growth of mould, insects and damp, therefore keeping fresh in an extended period of storage.