In each step of mass production, D&D arranges a quality control department to ensure that each production department fulfills its responsibility of producing high-quality products.

D&D test products are often performed on the testing machine to ensure that the products comply with ANSI/UL standards..

D&D uses measuring tools to inspect the products during each process of mass production to ensure that the product size meets customer requirements.

In order to ensure consistent quality, during the entire mass production process, D&D will check and control each process well.

D&D uses the salt spray test machine to test the product to ensure that it meets the specific corrosion resistance requirements.

D&D test products are often performed on the testing machine to ensure that the products comply with CE/UL/ANSI standards.