Double Rhomb 双菱 is a translation of Beijing Watch Factory's major domestic brand name, Shuangling. The 40 jewel automatic was its top-of-the-line model, and has the highest jewel count of any vintage Chinese watch. This English-language example provides evidence that some Shuangling automatics were intended for export. Its movement is not completely original, however, as it appears to be an assemblage of parts from more than one movement.  Under the balance is a date code and 中国 上海 (China Shanghai).