Zuanshi

Zuanshi (钻石牌, "Diamond") traces to a 1932 Shanghai clock factory that was rebuilt in 1938 and began producing Diamond-brand alarm clocks; nationalized in 1955, it made Diamond-brand pocket watches from 1958 and, as the renamed Shanghai Stopwatch Factory from 1966, military stopwatches including China's first 1/100th-second stopwatch in 1963. It is unrelated to the similarly glossed "Diamond Flower" (宝石花) brand of the separate Shanghai Watch Factory No. 2. (Chinese Watch Wiki)

Cataloged watches