This is the same machine as the Ascaso Steel Uno Professional except that it has a smaller brass boiler (~225cc) and a 57mm portafilter grouphead and handle. This machine's three way solenoid valve only acts to relieve the pressure in the grouphead immediately after the extraction is complete. However, by design, it will not dry the extracted puck as well as the Professional version of this machine. On the flip side, this machines does a much better job with E.S.E. espresso coffee pods when compared to the professional version.