The Red Flag 20 is actually a copy of Leica M3 and M4, and possibly the only one in the world. Mao's wife, Madam Jiang was very keen on photography. She worked as an actress in Shanghai in 1930s and had several affairs with some stars of that period. During the Cultural Revolution, Madam Jiang's role was mainly to control the arts movement for the campaign's propaganda. Being loyal to Mao, she took a quite number of Mao's portraits and published them under different pseudo-names. When the then Iranian king visited China, Madam Jiang was presented with Leica M3 as gift which she adored immensely. In 1970s, production of sophisticated cameras was regarded as a symbol of a country's industrial strength, particularly for developing nations. And also in the 1960s and 70s, China was pursuing an economic policy of absolute self-reliance and attempted to produce anything it needed. Against this background, Madam Jiang ordered the copy production of Leica M3 and gave her M3 to Shanghai Camera Factory to dissemble. The copy production of Leica M3 was a huge challenge to China's manufacturing industry. Every parts of the original M3 were measured and then hand-copied. Many institutes, universities and research centres were involved in the process and special glasses were imported from East Germany. The first batch of Red Flag 20 kit came out in 1973 with three lenses, 35mm f1.4, 50mm f1.4, 90mm f2, exact copies of Summilux and Summicron. But the Shanghai Camera Factory also made some modifications, including the back-door film loading mechanism. However, the production cost was unsustainably high. So only a total of 187 cameras rolled off the production line. The quality of the Red Flag 20 is said to be a long way behind Leica but is of great collection value due to its rarity and special history.