What does GDTD on gdtd mask mean?

It's short for mask manufacturing company. GDTD, namely Guangdong Tongde Pharmaceutical Co., Ltd., was established on September 27th, 2003, located at No.4, Xiwu Road, Shenchuan Avenue, Zhanjiang City, Guangdong Province. The business scope includes production and sales: drugs, medical devices, masks, cosmetics, disinfection products, food, industrial flavors and fragrances, sanitary products, oral cleaning products, washing products, daily chemical products, chemical products, biochemical reagents, daily necessities, plastic raw materials and products (excluding items prohibited from production and sales in the Catalogue of Plastic Products Prohibited in Guangdong Province). Import and export of goods or technologies (except those prohibited by the state or involving administrative examination and approval); Loading and unloading (except port loading and unloading of hazardous chemicals), handling and storage (except storage of hazardous chemicals and hazardous wastes); Stem cell technology; Research and development of immune cell technology; Research and development of cell therapy technology and transformation of results; Cell storage service; Own property leasing service; Health services; Chinese herbal medicine planting, processing, marketing, technology research and development.