Some of the others on this site are Chinese forgeries. This is the real one.
Power cables can make a big difference on performance. This depends on how much RF is your space and how good the power supplies are in your equipment.
Some power cords make a negative difference because they change the impedance to cause a difference to trick you.
I would say that only 30% of the power cables on the market are legitimate improvements. This is one of those.
Review
Isoclean may not have intended for the Supreme Focus to supplement the limitations of connected equipment’s power supply system, yet the fact that the power cable would allow equipment to rid itself of its old sonic shell is certain. To use such a powerful tool in review sessions will constitute irresponsibility on the part of the reviewer, for the Supreme Focus will transcend the finesse of equipment to beyond recognition and reasonability, so much so that conclusion drawn from such sessions can hardly represent any value whatsoever to the readers.