During the Cultural Revolution, Chairman Mao 胸章 (毛主席像章) became one of the most produced collectibles in history — over 4.5 billion were made. Today they're sought-after antique items.
mistakes
Don't confuse with 胸卡 (xiōngkǎ, ID badge worn on a lanyard). 胸章 is pinned with a pin/needle, often metal or enamel; 胸卡 is a clip-on or lanyard ID card.
