What is the difference between a dSF11, dSF12 and dSF20? digitalSTROM Support September 28, 2018 06:02 Updated Follow The filter has been constantly optimized (better filter performance, function display etc.). The dSF20 should be used for new installations. Related articles How many filters dSF need to be installed? How much power is required to protect a dSF filter? What is the difference between a dSM11 and a dSM12? Which smoke detectors can I use with digitalSTROM? Which server for which purpose?