According to the inquiry of doors and windows, Dedun security door is a first-line brand, which belongs to Shanghai Dedun Trading Co., Ltd., focusing on the research and development and innovation of high-end security doors, with advanced German equipment and leading technology and first-class product quality. De Dun security door has three subversive German technologies: German patented anti-pick steel technology, German patented automatic lock technology and German patented invisible lock core technology, and has developed a new generation of anti-pick technology "Doppelschutz-Sicherheitsür" and is in Germany.