During the production of heated shoe insoles-pu insoles, Dongguan S-King Insoles Limited divides the quality control process into four inspection stages. 1. We check all incoming raw materials before usage. 2. We perform inspections during the manufacturing process and all manufacturing data are recorded for future reference. 3. We check the finished product according to the quality standards. 4. Our QC team will randomly check in the warehouse before shipment. . We receive important feedback on how our existing customers' experience S-King brand by conducting customer surveys through regular evaluation. The survey aims to give us information on how customers value the performance of our brand. The survey is distributed biannually, and the result is compared with earlier results to identify positive or negative trends of the brand.. At S-King Insoles, we offer expertise combined with personalized, one-on-one technical support. Our responsive engineers are readily accessible for all of our customers, large and small. We also provide a wide array of complimentary technical services for our customers, such as product testing or installation..