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 What is the difference between a dSM11 and a dSM12? How many filters dSF need to be installed? How much power is required to protect a dSF filter? How can I install dSF filters in conjunction with ELCB (earth leakage circuit breakers)? Which Doorbird devices are supported?