Zenith is more than just a well-known Swiss watch and movement manufacturer, many of their timepieces have changed the history of watchmaking. The El Primero launched in 1969, for example, featured one of the world’s earliest automatic chronograph movements that famously beat at 5 Hz, i.e. 36,000 times per hour and measured at 1/10th of a second. Before Rolex started developing their in-house movement, their Daytona was made manufactured using Zenith’s El Primero movement deliberately reduced to beat at 28,800 times per hour for better stability.

Zenith’s latest creation, the Defy El Primero 21 boasts the El Primero 9004 automatic chronograph movement that powerfully beats 360,000 times per hour (50 Hz) at the speed of 1/100th of a second each, while the central hand rotates at a rate of once per second. Years ago, Tag Heuer, under the LVMH watch group also introduced a 1/100-second mechanical chronograph, the Carrera Mikrograph, but the mechanism of the El Primero 9004 movement is different and brand new. Compared with the previous El Primero movement, the diameter of the new generation has increased from 30 mm to 32 mm, with the thickness increased from 6.5 mm to 7.9 mm, with the number of parts reduced from 278 to 203. The new timepiece has 50 hours of power reserve and is COSC-certified and magnetic resistant to 15,000 Gauss.