I'll tell you that the duckling's after-sales are all temporary workers found by local manufacturers, and the special after-sales have been banned by the manufacturers. Therefore, I am one of the victims (maintenance personnel) for the delay in solving the quality problems. If the quality problems occur, they will be attributed to the maintenance personnel. After deducting your installation and maintenance fees, the duckling manufacturer has hurt me, so I will tell you the truth and buy products of big brands, and don't try to buy products like Duckling cheaply.