This replica explorer 16550 represents the reference that established the Explorer II as a true dual-time-zone instrument, adding a fixed 24-hour bezel and independent hour-hand adjustment to the 40mm stainless steel case. The black dial with luminous markers and a distinctive orange 24-hour hand creates one of the most legible layouts in the catalog. At 40mm, this predates the modern 42mm 226570 and wears noticeably more compact on the wrist. The Oyster bracelet and screw-down crown maintain the tool-watch credentials.

Technical Overview

• Case diameter: 40mm
• Case material: stainless steel
• Bezel: fixed 24-hour with engraved markings
• Dial: black with luminous markers and orange 24-hour hand
• Crystal: sapphire, flat
• Bracelet: Oyster with folding clasp
• Movement: automatic with GMT function
• Functions: hours, minutes, seconds, date, 24-hour hand

The fixed bezel differentiates the Explorer II from the GMT-Master, which uses a rotating bezel for dual-timezone tracking. On the 16550, you read the second time zone directly from the orange hand against the bezel markings, a system designed for speleologists and explorers who lose track of day-night cycles.

Inside the Movement

The automatic movement includes an independently adjustable hour hand, meaning you can change local time in one-hour jumps without stopping the seconds hand or affecting the GMT hand. This quick-set functionality made the Explorer II a practical travel watch rather than just a cave-diving instrument. The orange 24-hour hand has become the visual signature of every Explorer II since this reference. For a comparison with the latest iteration, the 226570 in 42mm shows how the design evolved while keeping the same core functionality. Both share a place in the Explorer collection, connected by the fixed-bezel GMT concept.

What Sets It Apart

The 16550 holds a unique position as the reference that established every design code the modern Explorer II still follows. The 40mm case is slimmer and more proportional than the current 42mm versions, and the bracelet taper gives it a vintage wrist feel that newer models cannot match. Black dial references from this era are valued for legibility: the high-contrast combination of white markers, orange GMT hand, and black background makes time-reading instantaneous. This replica explorer 16550 is the original expression of the dual-time Explorer II concept in its most purposeful form.