Zenith caliber El Primero 9004
El Primero 9004 description
Self-winding movement with cam-actuated chronograph capable of measuring up to 1/100 of a second. The chronograph runs on its own escapement system, with a balance wheel operating at 360.000 bph. The power reserve for the chronograph is 50 minutes, and it is wound by hand. The balance for the regular timekeeping runs at 36.000 bph and is wound either by hand or through the oscilating weight. Both balance springs are made of 'carbon-matrix carbon nanotube composite'. The central hand makes one rotation every second; at 12:00 there's a power reserve indicator for the chronograph.