This is a milestone year for A. Lange & Söhne as it completes 25 years since it was resurrected after the reunification of Germany. The celebrations began in January this year during SIHH and the brand has said that it will release a limited edition from its iconic Lange 1 collection every month until October 24 this year for a total of 10 watches. We’ve already seen and covered four of them: the Lange 1 “25th Anniversary,”  the Grand Lange 1 Moon Phase “25th Anniversary,” the Little Lange 1 “25th Anniversary,” and the Lange 1 Tourbillon Perpetual “25th Anniversary.”

The color codes of the Lange 1 silver jubilee editions abide

This month sees the release of the latest, a special anniversary edition of its cleverly engineered GMT watch, the Lange 1 Time Zone. Like its predecessors in the 25th Anniversary collection, the watch is limited to just 25 numbered pieces in white gold and features blued steel hands and blue details on its solid silver argenté dial, which is designed to allow the wearer to read his or her home time, as well as the time in a second time zone, simultaneously.

A second-time-zone subdial adds to appeal

To set the second time zone, one simply presses the lateral pusher in the side of the case at 8 o’clock to advance the rotating city ring — inscribed with the names of 24 world cities, each representing one of the 24 major time zones — in an easterly direction. At the same time, the hour hand on the second-time-zone subdial at 4 o’clock will move forward by one hour with each press of the pusher. The watch also has a synchronization mechanism that enables the wearer to transfer the time zone indicated on the subdial to the main dial.

Like previous versions of the Lange 1 Time Zone, the first of which made its debut in 2005, the watch’s array of functions includes a day-night indicator (overlapping the corner of the second-time-zone subdial); an outsize date for the home time (in a double window at 2 o’clock, with quick setting by the pusher at 10 o’clock); and an “up/down” (“AUF/AB”) hand-type power reserve indicator between 2 and 4 o’clock. The case measures 41.9 mm in diameter and 11 mm thick.

The balance cock has the 25th anniversary engraving

The 25th Anniversary piece contains Lange’s manual-wound, in-house Caliber L031.1, whose numerous decorative enhancements are visible through a sapphire caseback. The movement has 54 jewels, a screw balance, four screwed gold chatons, and a lengthy 72-hour power reserve, along with the typical Glashütte three-quarter mainplate and bridges made of untreated German silver.

VIDEO: A 1-Minute Review of the Lange 1 ‘25th Anniversary’ Edition

Made of 417 parts, it has been assembled, disassembled, and re-assembled a second time before being fitted into the case, a process that speaks to Lange watchmakers’ dedication to immaculate quality control. Continuing the visual theme of the anniversary series, the balance cock is engraved with a blue-filled, relief-engraved numeral “25” in the same familiar font as that used for the outsize date.

The Lange 1 Time Zone “25th Anniversary”comes on a hand-stitched dark blue alligator strap with a gray contrast seam and a white-gold pronged buckle. It is priced at $52,800 and available in select Lange boutiques.