Each section is 3.2mm thick and 15mm wide. Folded length is 23cm.
They feature spring-loaded stops to click the sections in firmly at 0 degrees (when folded), 90 degrees and 180 degrees. They can't flop around while in use, and require a deliberate action to close them up after everything is measured.
These rulers are non-conductive, unlike measuring tapes.
Shinwa Rules Co., Ltd. was established in 1971 by the integration of three measuring instrument manufacturers: Watanabe Doki Seisakusho, Hanyu Keiki and Watasei Doki Seisakusho. At that time, the primary concern was enhancing the productivity of our manufacturing plants in anticipation of a rapid increase in production volume due to Japan’s dramatic economic growth. For that reason, they installed automated plating machinery and extended manufacturing plants. They also installed a wastewater treatment facility to make sure hazardous materials did not leak out with our discharged water; Shinwa were an eco-conscious corporation even back then.