Hey @amtprod ,
Furman units with SMP are series mode surge protectors. Like ZeroSurge or Brickwall. What they all have in common is they have a low pass filter at the start of the surge protection circuit, which is another word for "noise filter."
This low pass filter is active around 3kHz and higher, which is a lot lower than EMI/RFI filters, a good thing.
Furman also adds LiFT, an active linear filtering technology to further reduce noise. While the strip is designed to reduce noise coming in, it also effectively reduces noise above 3 kHz going out, making it a great candidate for wall warts.
The low pass filter slows down a voltage surge long enough for the rest of the circuitry to have time to respond to it. Some parallel mode surge strips also incorporate some sort of low pass filtering for similar reasons.