What is the fine-grained topic of the following text: In 1969, Zenith made its stellar contribution to the chronograph saga with the El Primero (meaning ‘the first’ in Esperanto): an integrated automatic column-wheel mechanism beating at the high frequency of 36,000 vibrations/hour (5Hz) enabling it to reach chronometer-certified tenth of a second precision. Only return the topic.
Zenith El Primero Chronograph's Features and History