Here : this is from the link you posted. At the bottom...
The ENO is filtering RF Interference or 'noise'
Permalink On Mon, 09/11/2020 - 11:56am
The review is a non-technical review based on Chris Kelly's listening experience, in his system, while using the ENO and matching Streaming cable.
As the designer of ENO I can answer your questions. Firstly we must establish what the reason is that a lot of streaming devices don't quite achieve the level of sound quality of Hi-End CD and vinyl. Our research has proved that the digital input circuitry of streaming devices is very sensitive to the effects of RF interference or 'noise' that is present mixed in with the Ethernet signal when it's delivered into the RJ45 socket on the back of the streaming device. The Ethernet signal passes through the ENO filter unaltered, it arrives at its destination untouched, fully intact. The RF interference that's also in the cable is filtered out and absorbed as heat within the ENO Filter. So what arrives at your streaming device is pure unaltered clean data, not noisy mushy data. The difference in sound quality of pure clean data to noisy mushy data is quite astonishing.
The device is made by hand using the best quality components possible, it's labour intensive to produce, and that, combined with the lift in sonic performance you get, makes it very good value for money.
By RichTruss