At first I had trouble with it because it gave me a an error code 35. Then I filed a dispute and seller responded immediately. they were extremely supportive. After several attempts to activate the product, the best option for me was to was to flash it using an Android phone. I confirm that i seem to be the authentic Ninebot controller on the account that the Segway app is registering my milage and I'm able to receive points. But on the other hand...my charger doesn't fit in the socket probably. Its not a tight fit and it slips out easily. I haven't connected my external battery yet but I'm already reaching 30kmhr without it. This seller seems legit.