You're probably thinking of the Xiongda YTW-06 that you can buy directly from Xiongda. You have to buy the special controller with it, and it's best to buy the pedal sensor and throttle with them because everything from Xiongda is pretty cheap.
You can only buy the bare motor, so you have to find your own rim and spokes to build the wheel. The jury's out on reliability. the first version did have some reliability issues, but they've had a lot of time since then to improve them.
It's a similar story with the Keyde motor, which is a similar size. The Keyde has a lot of different versions, some of which have internal controllers that are best avoided. You also have to buy these direct from Keyde.
Lastly, if you want solid reliability, there's the Q100, which is 2.2kg, and you can only get it from Chinese suppliers like the previous two.