The first phase coupler I bought on Amazon, but was not suitable for 500Mbit D-Lan's. When I had to, because it is urgent to shop locally and there arose the "KEMO M091N Phase Coupler". What can I say? - Short and simple: The PowerLine AV 500 from Netgear are finally without interruption with the highest transfer rate it! It is important that the expert necessarily adheres to the requirements of the Instructions ;-)