El Primero
Zenith’s high-frequency automatic chronograph movement family, first launched in 1969.
Also known as: Zenith El Primero, El Primero calibre
Definition
El Primero is Zenith's integrated automatic high-frequency chronograph calibre family, unveiled in 1969. The original architecture combined automatic winding, an integrated chronograph and a 36,000-vph (5 Hz) escapement, allowing timing displays capable of resolving tenths of a second in suitable configurations. The calibre has evolved substantially while retaining its high-beat identity.
Why it matters
Its significance comes from the combination of automatic chronograph architecture and high frequency; 'El Primero' should not be used as a generic term for any 5 Hz chronograph.