Originally Posted by zacster

The difference between those is just the plug at the dynamo. For some reason they use different connectors. For the Shimano I have, you take the bare wires and push it through the top part, wrap it up, and click it onto the hub. I think the SON uses flat disconnects that you can buy at any Radio Shack or Home Depot, but are probably also supplied with the hub and pre-wired for this device. I don't know why one would be more expensive than the other.