What is a Seiko mod? The complete guide to choosing yours

Seen Seiko mods on TikTok or Instagram and wondering what they really are? In this guide, we explain in simple terms what a modified Seiko watch is, what's inside, the different styles available and how to choose yours with confidence.

What is a Seiko mod?

A Seiko mod (or "modified Seiko") is a watch built around a Seiko movement, with some or all of the visible parts swapped out: the dial, hands, bezel, case, crystal or strap. The goal: create a watch with a unique style and the reliability of a proven Japanese movement.

Seiko mods started in a community of enthusiasts who customized their own watches. Today, workshops like Eternal Mods assemble them by hand to offer high-end looking watches at an accessible price.

Why start from a Seiko base?

Seiko movements are among the most widely used in the world for a simple reason: they are robust, accurate and easy to service. There are tons of compatible parts, which makes almost any style possible while keeping a reliable heart.

The movements you'll find in a Seiko mod

• Seiko NH35A (automatic): no battery, the watch winds itself with the motion of your wrist. This is the movement in most of our three-hand watches.
• Seiko NH34 (automatic GMT): the same automatic base, with a fourth hand to read a second time zone. Ideal if you travel or have family abroad.
• Seiko VK63 (quartz chronograph): a very accurate battery-powered movement, with a chrono hand that snaps back to zero. No winding needed.

Automatic or quartz? If you love watching the seconds hand sweep and the idea of a "living" watch, go automatic. If you want a watch that always keeps time without thinking about it, the quartz chronograph is for you.

The different Seiko mod styles

There's a Seiko mod for every style. Here are the main families:

• Chronograph: the ultimate sporty-chic look. Discover our Seitona collection.
• GMT: two-tone 24-hour bezel and two time zones. See the GMTeiko collection.
• Diver: rotating bezel, luminous hands, steel bracelet. See the Subeiko collection.
• Classic: fluted bezel and magnified date, for everyday wear. See the Justeiko collection.
• Day-Date: the day and date at a glance, our dressiest style. See the Dayteiko collection.
• Octagonal bezel: integrated bracelet and sport-chic design. See the Royal Eiko collection.

Rather build your own? With our Seiko mod configurator, you choose the dial, bezel, hands and strap, with over 20,000 possible combinations.

Is a Seiko mod a "real" watch?

Yes. A Seiko mod is a real mechanical or quartz watch with a genuine Seiko movement inside. It isn't a luxury watch and isn't sold as one: it's a customized watch that borrows popular design codes, at an accessible price. Eternal Mods is an independent workshop and is not affiliated with the Seiko brand.

How to choose your Seiko mod

1. Style: sporty (chronograph, diver), travel (GMT) or dressy (classic, day-date).
2. Movement: automatic for mechanical charm, quartz for simplicity.
3. Size: our models are around 39 to 40 mm, a size that suits most wrists.
4. Strap: steel for a dressy look, rubber for comfort and sport, leather for a more classic style.

How much does a Seiko mod cost?

The price mostly depends on the movement and finishes. At Eternal Mods, watches start at €209.99, with 316L stainless steel, scratch-resistant sapphire crystal and water resistance tested to 10 bar on every watch. You can pay in installments with Klarna.

How to care for your Seiko mod

• Clean the case and bracelet with a soft, slightly damp cloth.
• Avoid hard knocks and strong magnetic fields (speakers, magnets).
• For an automatic: if you haven't worn it for a few days, give the crown a few turns to wind it before setting the time.
• If your watch has a screw-down crown, remember to screw it back in after setting it.

Seiko mod FAQ

Is a Seiko mod water resistant?
At Eternal Mods, every watch is tested to 10 bar before shipping. It handles everyday wear and swimming.

How long does delivery take?
Your watch is assembled, tested and then shipped with tracking. Allow 3 to 12 business days after your order, with free shipping.

What if I don't like it?
You have 30 days to change your mind, and every watch comes with a 2-year warranty.

Find your Seiko mod

More than 2,000 customers already wear an Eternal Mods watch. Browse all our Seiko mods and find the one that fits you.