Jaeger-LeCoultre Master Control Q4138180 40 mm Grey Dial

The Master Control Q4138180 shares the collection's 40 mm round stainless-steel case and 12.05 mm thickness with an expressive grey sunburst dial. Applied markers, pushers and the see-through caseback give the layout mechanical presence, while the display combines a chronograph, 30-minute counter, pulsometer and chronograph seconds with the day, date, month and moon phase. A deployant clasp, sapphire crystal and 50 metres of water resistance round out the unisex specification.

Inside, in-house Calibre 759 is an automatic chronograph measuring 25.6 mm across and 6.85 mm high. Its 367 parts include 36 jewels, and its 4 Hz frequency supports a 65-hour power reserve. A full rotor supplies winding, while the column wheel and vertical clutch govern the chronograph operation. Cotes de Geneve bridges are visible through the back, and the functions extend to the day, date, month, moon phase and small seconds.