Meets fundamentally their purpose

By pumping the air, the oxygen content decreases in the container and which protects a limited extent the coffee beans a little loss of quality. However, I must clean in some time intervals the rubber seal with a damp cloth, so that pumping also effective and the vacuum is maintained in the vessel.

After two years of use at the time the pump supplied is unfortunately no longer be used, because they no longer pumping.
With a new pump but it worked again (). This new pump also signaled with a click when the intended vacuum is reached. Perhaps this type of pump is now also used for the new containers.