I use the Nano Co2 system ProFlora U201 now for 4 weeks, the content was very well packed and in perfect condition. The manual is clear and understandable written and maintained in multiple languages. The construction of the CO2 system just went out of hand and was also very well explained in the manual. The indicator test is also working very ordenlich and could be quickly put to use. Setting the number of bubbles for the desired amount of CO2 in the water is quite simple. You have to at the desired level of CO2 in several steps grope to the Co2 value fits. Among the parts: All parts included in the delivery were working very good and clean, no burrs present on the plastic parts. The bubbler was close and could be used in my case without any complaint.
All in all, the Nano Co2 system worth every penny.