Hamilton just added a useful new feature to its iconic Khaki Field

Field watches are famous for their simplicity, so whenever a complication is added to their no-fuss dial, it’s always worth a closer look.

In this case, Hamilton has given its iconic Khaki Field a power reserve indicator, which helpfully shows at a glance how much of its massive 80 hours of power reserve remains.

Housed at the nine o’clock position, the indicator resembles that of a fuel tank, with F for full at the top, E for empty at the empty, and “½” half-way between. It’s a nice way of adding extra functionality to a watch that is otherwise built to major on simplicity and legibility.

The dial includes a 24-hour scale, illuminated hands and hour markers, and “Power reserve / 80 hours” written at the six o’clock position.

The 40mm stainless steel case diameter remains unchanged at 40mm, while the thickness has increased slightly (to 11.95mm) to accommodate an exclusive new movement. Dial colour options remain unchanged, with black or white, and strap options include a green textile NATO strap or a stainless steel bracelet. Water resistance is 100 metres.

Inside, the watch is driven by a manually-wound H-23 calibre mechanical movement from ETA. The movement has a slipping clutch, so even when fully wound it’s still possible to keep rotating the crown without overwinding or damaging the movement.

The use of a slipping clutch with the differential also protects the movement from shock damage. Hamilton explains: “As the differential relies on friction, a string shock can cause one of its plates to shift relative to the other. This may lead to a desynchronisation between the power reserve hand and the actual state of the mainspring…[A slipping clutch] allows the system to resynchronise automatically during winding, without requiring intervention or servicing.”

Available to order now, the Hamilton Khaki Field Mechanical Power Reserve is priced at £760 with a NATO strap and £840 with a steel bracelet.