Pump properly and quietly performing work-out. The concept of filling in a closed container is attractive. However I met quite quickly an air lock valve problem during aspiration (that is released when a totally random ... or not) prevents complete emptying and forcing me to finish it with an electric pump previously purchased (at a price much lower and still working). So I hereby issue a strong doubt on the durability of this product ... infuriating given the high pump prices and oil ... if you fail to finish your drain and are forced to recover from the clean oil in an oil stained background unaspirated. But maybe I'm fell on a bad run?
