A&D Company, Limited is a Tokyo, Japan based manufacturer of measurement equipment such as digital blood pressure monitors, scales for medical and home use, ultrasonic nebulizers, as well as analog-to-digital and digital-to-analog converters for semiconductor manufacturing equipment and electron guns. "A&D" stands for "analog and digital" and is represented without any spaces It was founded in 1977 by a group of 13 engineers who left Takeda Riken Industry Co., Ltd. in Japan and was first listed on the Tokyo Stock Exchange in March 2006 as symbol 7745. Wikipedia