[New in 2026] Seiko Astron Nexstar HAC001J | Radio-controlled solar x titanium x 5 countries reception, making a high-quality business watch even slimmer

Seiko Astron NEXTER (NEXTER) line as a new model in April 2026HAC001Jwill be added.
The equipped movement is Cal.7B72 radio solar. It receives standard radio waves from five countries: Japan, China, America, Germany, and the United Kingdom, and always maintains accurate time. This is a true business watch with a pure titanium case, diamond shield coating, and sapphire glass that weighs only 90g.

Although it belongs to the same Nexstar line as the higher-end model HAD001J, it has a slimmer case size and a price of 165,000 yen, making it the easiest choice to enter the world of Astron. The navy dial and pink gold color accents exude elegance and will blend naturally with both suits and casual wear.

The moment you put it on your arm, it elevates its status.

A piece that makes a picture even if you line it up or look at it.

The depth and dignity of the navy dial.

HAC002J (related color)

Astron finishes without compromising on details.

HAC001J Front: Navy with a clean feel.

HAC001J Detail—density of texture.

■ Main features

• Equipped with Cal.7B72:Radio solar, average monthly difference when not receiving ±15 seconds
• Radio wave correction function:Automatically and compulsorily receives standard radio waves from five countries: Japan, China, America, Germany, and the UK.
• Approximately 9 months of operation when fully charged:Approximately 2 years with power save. You can continue using it without worrying about running out of battery.
• Pure titanium case + diamond shield:Seiko's unique hard coating that is lightweight and scratch resistant
• Sapphire glass:Excellent visibility with super clear coating
• Clasp with smart adjuster:One-push three-fold method allows fine adjustment without tools
• Slim case design:45.5mm long x 39.5mm wide x 10mm thick. Fits neatly into the cuff
• 10 ATM waterproof:Reinforced waterproofing for daily life so you can feel safe around water
• Equipped with Lumibrite:The hands and indexes are easy to see even in the dark
• Metal allergy resistant:Designed with consideration for those concerned about metal allergies
• Time difference correction function:Easily adapt to time differences at your destination
• Fully automatic calendar:Automatically manage your calendar until December 31, 2099

■Specs

■ “Ease of use”: reception in 5 countries x 9 months on full charge

The standard radio waves that Cal.7B72 can receive are Japan, China, the United States, Germany, and the United Kingdom. Once you experience the peace of mind of knowing that the time will continue to be corrected automatically even when you're on a business trip or traveling, it's a convenience that's hard to let go of. Even in environments where reception is not possible, high accuracy is maintained with an average monthly difference of ±15 seconds when not receiving reception.

What's even better is that it has a long battery life of about 9 months when fully charged. This value exceeds the higher-end model HAD001J (approximately 6 months), and it will last approximately 2 years in power save mode. You can keep it on your wrist without worrying about it running out of charge - this is the essential reason to choose radio solar.

■ “Everyday fit” created by the slim case

Case size is 45.5mm long x 39.5mm wide x 10mm thick. Weighing approximately 90g, it is light enough for a full metal pure titanium model, but its thinness makes it particularly compatible with suit cuffs. The band can be adjusted up to a maximum of 190mm, and is designed to fit a wide range of people with narrow arms.

It's a little more compact than the higher-end model HAD001J, so it's a great option for those who want to put together an elegant collection without making too much of an impression. The size embodies the "just the right adult feel" for business situations.

■ High durability: pure titanium x diamond shield

The case and band are made of pure titanium. It is a lightweight and corrosion-resistant material that maintains its beautiful condition for a long time. In addition, Seiko's unique Diamond Shield coating significantly improves surface hardness. It is highly resistant to daily fine scratches, and its appearance will not deteriorate even if it is used hard every day.

Super clear coating is applied to the sapphire glass. Minimizes reflections in the field of view and vividly displays the expression of the navy dial. Lumibrite on the hands and indexes also ensures visibility in dark indoor spaces and at night. It's a book with a high density of functions.

■ HAC001J and HAC002J——Choose from two colors

HAC001J has a navy dial x silver band. It has a calm and elegant look and is a coloring that can be used in a wide range of situations, mainly in business settings. The sibling model HAC002J has different color variations, so it's fun to compare them side by side and choose the one that suits your style.

Both have a clasp with a smart adjuster mechanism, and are comfortable to wear because they can be finely adjusted without tools. It also has a metal allergy resistant design, so you can trust that it is gentle on your skin.

■ Recommended for these people

• Those who want to try Astron's radio solar at an affordable price
• Those who want to keep their cuffs neatly organized with a slim case
• Those who value the lightness and durability of pure titanium
• Those who want to eliminate the hassle of setting the time by adjusting radio waves
• Those looking for a dressy watch with a navy dial
• People who often travel overseas and want a time difference correction function
• Those who are thinking of gifts for milestones such as promotion, employment, retirement, etc.
• Those concerned about metal allergies

■ Buyer's comment

The first thing you notice when you pick up the HAC001J is how thin and light the case is. The Astron Nexter line was originally designed as an Astron for everyday use, but the HAC001J goes one step further and stands out for its ease of fitting into the cuff. The long running time of 9 months on a full charge is also a point that can be recommended with confidence especially to those who are new to radio solar. At 165,000 yen, this quality makes it a perfect choice as a gift.

— Nanapure Buyer Fujimuro

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