If the product fails during use, after receiving the customer's call or fax notification, explain the handling measures to the customer within 1 hour; from the time of receiving the service information to the time of arriving at the fault site, arrive at the construction site within 500 kilometers and 24 hours, and 1000 kilometers Arrive at the construction site within 36 hours within 36 hours, and arrive at the construction site within 48 hours within 1000-2000 kilometers for maintenance and troubleshooting. After-sales service engineers are on standby 24 hours a day, without holidays, if the fault is not completed, the service engineer cannot leave the site, and the customer's permission is required to leave the site.