I have bought this – overall it looks like the build quality is good, however it is not balancing, and not protecting when cell voltage is different .. watch this video
here are BMS that really works:
Aliexpress Daly BMS: https://bit.ly/2IkIaYu
Aliexpress Smart BMS: https://bit.ly/3nJeRPg
spot welder link: https://bit.ly/3nOhsYu
Ebay Daly Smart BMS: https://ebay.to/3lzRQN1
Amazon: https://amzn.to/33Uit9D