... , scene explanation and so on. Shenzhen Xuezhiyou Technology Co., Ltd. specialized in reading pen OEM, ODM, book Design ... sales, we have business with customers from South Korea, Japan, Middle East, Singapore, the United States, Britain, France ... . Product Quality Assurance:Products of Shenzhen Xuezhiyou Technology Co., Ltd. have already passed national 3C certification, ISO9001 international ...