It is a network switch that is sold by Chord and does come with a network cable which is meant to go from the switch to the NDX 2 streamer. You will find a thread regarding the English Electric 8Switch here.
I held off for months then I called my dealer and he them in stock and gave me a new one to demo. From the moment I plugged it in I heard an improvement. Within a couple of weeks I called him and gave him my credit card number over the phone.
That is my experience, my system in my room with my ears. Check it out but there are many comments regarding the switch in the thread I mentioned above.