Zuanshi 钻石 SM1A-K 152 1

Zuanshi 152 pattern

Zuanshi watches with the SM1A-K movement continued to be manufactured when the factory changed its name to Shanghai No. 4, but most of the models with no calendar had caseback numbers of 151 (chrome-plated) and 152 (stainless steel). This is an example of the latter with an uncommon colour pattern dial. It dates to February 1979.