I bought mine from Eco ebikes headquartered in Nashville. But since then they have provided zero support. I believe they programmed the controller and custom rigged the wiring harness. Otherwise the battery and motor come pretty much direct from China along with very poor documentation. The documentation is almost useless. Eco E bikes makes a big deal about TS open firmware but provides almost no support. They don't even have a decent video about how to set up the stock variables on the simple display . No explanation of why a person should mess with complicated open firmware, not even the baseline factors they programmed at the factory.