After 8 months, the motor brush stopped turning. When parsing, it turned out that the slot on the working gear cost! It's all plastic. Metal shaft and plastic slot! Therefore, the shaft rotates. You can change it and it will happen again. The ventilation grill on the motor brush was deformed due to temperature. No wonder they are on Ali under 6000 and people are buying up! 1 seller has 40 purchases! Sadness!