All our measuring instruments (especially calipers, paint thickness gauges, and refrigerant pressure gauges) are calibrated quarterly according to ISO quality management system requirements to ensure the data we provide you is objective, accurate, and reliable.

We use an internationally certified electronic signature platform (such as DocuSign or Adobe Sign). Each signed contract generates a digital certificate with a timestamp and encrypted hash value, which has full legal defense effectiveness in international arbitration courts.

We cannot open each tire to inspect the inside. However, if a visual inspection reveals severe creases on the tire sidewall, it indicates that the run-flat tire has been driven for a long time at zero pressure, damaging its internal structure. We would recommend replacing it before shipping.