Hand-wound chronograph movement numbered and signed Breguet. Power reserve indicator and 20-minute counter engraved on the back of the movement. Chronograph running indicator at 6 o'clock. Cal. 580DR. 16 lignes, 62 jewels. 55 hours power reserve. Symmetrical inverted in-line lever escapements with silicon pallets. Breguet balance-wheels on Breguet springs in silicon. Movement frequency 3Hz; chronograph frequency 5Hz. The two oscillators are adjusted in six positions.
Pictured from dial-side.