Some of our factories have achieved ISO9001:2015 certification and all factories follow ISO9001 quality management system. To guarantee the quality of our products, our Quality Department tests at least 4 times the whole process. The first time, the inspectors test the raw materials and take records when the raw materials arrive the plant. The second time, we carry out quality inspection during production. The third time, we carry out quality inspection before put it in storage. The fourth time, we spot check again before loading.