ED operates the production management system of strict and complete quality control by using advanced measuring devices such as its exclusive tester, together with the construction of automated facilities in order to improve the product quality and production efficiency. Since the tester, education equipment, communication devices require precision, reliability and endurance, the product reliability and completeness in its every state of production by constructing the whole manufacturing processes logically from the stock of materials to the forwarding of products. While trying every effort in manufacturing best products by reforming the quality from the phase of product design, ED are exerting all possible efforts in manufacturing the products which customers can really rely and use.