Just over two years ago, Seiko introduced the first Astron GPS Solar Dual-Time chronographs.
Since then, the brand has gradually released slightly updated versions with new materials and colors. For the company's 145th anniversary, Seiko has completely redesigned its Astron GPS Solar Dual-Time chronographs. The series received a new case and caliber, marking a full upgrade. The collection includes four new models: Seiko Astron GPS Solar Dual-Time Chronographs HAB001, HAB002, and HAB003 as regular updates to the lineup, and a limited anniversary edition HAB004 dedicated to the 145th anniversary. We had the opportunity to explore all four models in detail.
New Case - Key Update of the Series
Fans of the series will immediately notice several changes. The most important is the new case design. However, if you are familiar with the Astron line, you will recognize similarities with previous models. The new case is a logical step forward. Its diameter is 43.4 mm, and thickness is 12.4 mm. All four models are made of titanium with a super-hard coating. The case design stands out with its multifaceted profile and new two-component octagonal titanium bezel. The top part of the bezel is matte, while the faceted sides are polished. This combination of finishes accentuates the shape of the case and gives it expressiveness.
Updated Astron GPS Solar Dual-Time Chronograph Dial Design
Visually, the new model also differs in the dial layout. In previous versions, the sub-dials were positioned at 6, 9, and 12 o'clock. In the new model, they are shifted to 3, 6, and 9 o'clock, creating a more balanced and readable appearance. This was made possible by the new Seiko 5X63 caliber, which replaced the previously used 5X83. Besides the new positioning, the order of the functions displayed on the sub-dials has changed.
The main time is now displayed in the center, and the additional time zone on the sub-dial at 6 o'clock. As in previous models, switching between time zones occurs by holding two buttons for three seconds. When the chronograph is activated, the same sub-dial is used to count elapsed hours and minutes. The main difference is the new 24-hour scale on this sub-dial, which allowed the removal of the AM/PM indicator. In chronograph mode, the sub-dial displays elapsed time up to 24 hours.
Changed Sub-Dial Order and Additional Features
The multifunction sub-dial, which displays the day of the week, chronograph start status, battery charge, and flight mode, has moved from 9 o'clock to 3 o'clock. The sub-dial at 9 o'clock now shows chronograph time with an accuracy of 1/20 of a second - previously located at 12 o'clock. The date window is located between the indices at 4 and 5 o'clock, as in the previous version.
All three sub-dials have a concentric texture that contrasts with the main dial. The main dial is adorned with an intricate pattern of interwoven triangles, adding visual depth. At the same time, the dial itself serves as a solar panel for charging the watch. The flange with minute markings, steel hour markers, and internal UTC scale have been retained. The hour markers have been redesigned and now contain more LumiBrite luminescent material, significantly improving readability in the dark.
New Seiko 5X63 Caliber: Enhanced Functionality
The new 5X63 caliber has the same set of features as the previous one, including automatic time correction when changing time zones. If the setup signal is lost, the watch displays this on the dial. The accuracy of movement reaches ±15 seconds per month in the absence of a signal.
The caliber underwent significant changes: the layout changed from vertical to horizontal, which improved usability. The rearrangement of the sub-dials made the data reading order more logical. The caliber and design update clearly improved the user experience, deserving high praise.
Anniversary Model HAB004 for Seiko's 145th Anniversary
Let's take a closer look at the four models, starting with the limited edition HAB004. It stands out with a light-silver main dial with blue minute markings and sub-dials. This color combination creates a modern and vibrant image.
The watch comes with a lightweight titanium bracelet and an exclusive silicone strap in white and blue tones. Switching between the bracelet and strap has become very simple thanks to the new quick-change system: just press a button to remove or install an element. The system provides reliable fixation, making it one of the best on the market.
The anniversary model is released in a limited edition of 2,000 pieces and costs 3,000 euros. The price includes both straps and special packaging in a white and blue color scheme.
Three New Models in the Standard Line
In addition to the anniversary model, Seiko introduced three new options for the regular collection. The HAB001 is made entirely of titanium with a blue dial with gray notes. The HAB002 is also titanium with a black dial. The HAB003 features a black dial with gold-tone inner bezel, indices, and hands and comes with a black silicone strap.
Of the three standard models, I personally prefer the version with the black dial and titanium bracelet. However, the model with gold accents and silicone strap has a special charm and looks great thanks to the contrast.
The price of models HAB001 and HAB002 is 2,800 euros, while the HAB003 with a silicone strap is 2,700 euros. Additionally, Seiko offers white and black silicone straps compatible with all models in the series, costing 210 euros.
Impressions of Wearing the New Seiko Astron GPS Solar Dual-Time Chronograph Series
Testing the new series left a pleasant impression. Despite the increased case size and angular shape, the watch sits comfortably on the wrist. Ergonomics and balanced proportions immediately caught attention. The combination of matte and polished surfaces gives the watch sophistication.
The new titanium bracelet is well-made and equipped with a folding clasp with the Easy Adjust system, allowing for quick size adjustment.
Initially, I was doubtful whether I would like the updated design and comfort compared to the previous version due to the increased case and angular shape. However, after trying it on, all doubts vanished.
The watch fits well, and thanks to the lightweight titanium, it is comfortable to wear. The updated dial design with reconfigured function layout significantly improved usability. This is truly a quality series update.
All four models will be available on Seiko's official website, in brand boutiques, and from selected dealers starting in June 2026. Share in the comments which model you liked the most!