![](https://www.clarence.ch/3813-large_default/chronomaster-el-primero.jpg)
Original 1969 case with 38 mm diameter
Automatic El Primero column-wheel chronograph movement
El Primero Calibre 400: 278 components, 31 jewels and 36,000 VpH
Tachymetric scale on the inner bezel ring
Reference
51.2150.400/69.C713