D&D Hardware manufactures commercial door hardware for fire-rated openings from Jiangmen, Guangdong, covering concealed and butt hinges, mortise locks, overhead closers and panic exit devices. It publishes a UL Listing file number for each fire-rated family — R38013 for three-dimensional adjustable concealed hinges, R40486 for fire exit and panic hardware, R40717 for the DDDC-UL closer series and R40901 for mortise locks — all evaluated to ANSI/UL 10C three-hour positive-pressure criteria, alongside UL 305 file SA45817 for panic hardware. A parallel CE and UKCA range is certified to EN 1935, EN 1154, EN 1125, EN 12209, EN 1906 and EN 1303 for European fire doorsets. Holding both listings is unusual among Chinese hardware makers and suits projects governed either by an AHJ or by the Construction Products Regulation.