The initial production defects, as described in other reviews seem to have received WMF now under control. My Weinpumpe has nine months in operation and functioning properly. The application is easy: one of the two supplied locks a bit dampened, press the bottle and draw the air from the bottle using the pump.
In addition to the practicality of this model shows on the optics, even if the pump is bored most of the time in a kitchen drawer. The price-performance ratio is also good in my eyes.