A worker teaching young people how to check electrical machinery, according to the blackboard. The girl in the center and the boy on the right are wearing Red Guards signs, attached to their clothes with safety pins.
The slogan in the background on the right: Education must serve proletarian politics and must be combined with productive labor - 教育必须为无产阶级政治服务 必须同生产劳动相结合.
The impressum reads that this poster is a "Collective creation", with Xie Tulu, Fang Guansuo and  Pan Hesheng as actual makers.