Seiko mod: automatic mod watches with a Seiko movement
A Seiko mod is a mod watch built around a Seiko automatic movement. Ours are designed by Modus and run on the Seiko NH35. Ten ready-to-wear collections, or a configurator to build yours part by part. From €295, 3-year warranty, free shipping.
Ten collections of mod watches
What a Seiko mod is
A Seiko mod combines three things: a mechanical movement made by Seiko Instruments, a case, dial, hands and strap chosen one by one, and a final regulation. The expression comes from modding, the practice of enthusiasts who swap the parts of a watch to make it their own. The movement is the common base; the parts give the style.
At Modus Horlogerie, the watch carries our name and our dial. Seiko makes the movement and nothing else: the watch is designed, sold and guaranteed by Modus. So we say a mod watch with a Seiko movement, never a Seiko watch.
Which movement for which watch
All of them are Seiko Instruments calibres made in Japan. The exact calibre is listed on every product page.
- Seiko NH35
- Three-hand automatic with date: 24 jewels, 21,600 beats per hour, 41 hours of power reserve, hand winding and hacking seconds. It powers most models, including DEPTH, AXIS, ATLAS and FIELD.
- Seiko NH34
- The NH35 base with an independent 24-hour GMT hand, to read a second time zone. It powers the MERIDIAN.
- Seiko NH38
- An NH35 without the date, for a cleaner dial. It powers some PRISM dials.
- Seiko NH70
- Automatic with an open dial that shows the gear train and the balance wheel. It powers the ORBIT skeleton watches.
- Seiko VK63
- Meca-quartz for chronographs: quartz accuracy, a chronograph hand that sweeps the dial, an instant reset. It runs on a battery, so it is not automatic. It powers the INTERVAL and COSMOS.
Seiko Instruments rates its automatics at −20 to +40 seconds per day. That is the range for the movement alone; a unit in good condition usually runs well inside it.
The Seiko NH35 movement
At the heart of our mod watches is a Seiko automatic calibre, made in Japan by Seiko Instruments. The NH35 winds itself as your wrist moves, shows the date and stops the seconds hand so you can set the time precisely. 24 jewels, 41 hours of power reserve, and any watchmaker can service it.
Depending on the model, we also use the NH34 (GMT), the NH38 (open heart) and the NH70 (skeleton). Our INTERVAL and COSMOS chronographs run on the VK63, a meca-quartz movement.
All our movementsWhat a mod watch is, and what it isn't
A mod watch takes its cues from the great watchmaking classics: the dive-style watch, the dual-time GMT, the chronograph, the skeleton watch. It never uses another brand's name or logo. Every Modus watch carries only the Modus Horlogerie name, on the dial and on the caseback.
Build your own mod watch
In the configurator, choose the case, dial, bezel, hands and strap from hundreds of parts, with a live preview. Add an engraving on the caseback or the side, or your own logo on the dial.
Open the configuratorHow to choose a Seiko mod
Two watches can share the same movement and have almost nothing else in common. Here is what to check before you buy.
- The crystal
- Sapphire crystal resists scratches far better than mineral glass. All our watches have one.
- The case
- 316L stainless steel, the reference grade in watchmaking. If a seller only writes “alloy” or “metal”, ask for the grade.
- Water resistance
- 5 ATM at Modus: splashes and rain, not swimming or diving. That is why we say “dive-style” for the watches with a rotating bezel.
- The dial
- A dial without another brand's name or logo. On a Modus, only the Modus Horlogerie name appears.
- The warranty
- 3 years at Modus, an identified after-sales service and a service recommended every five years.
- The price
- Catalogue watches start at €295; the configurator starts at €349, options extra.
Delivery, shipping and returns
A catalogue watch ships within 24 to 48 business hours. A watch built in the configurator is prepared to order: allow 9 to 11 days, delivery included.
Shipping is free worldwide, with no minimum order. Outside the European Union, customs duties or local taxes may be charged on delivery. You have 30 days after receipt to change your mind; return shipping is at your expense unless the watch is faulty or not as described.
Looking after a Seiko mod
An automatic winds itself with the movement of your wrist. If it has stopped, give the crown 20 to 30 turns, then set the time. Do not touch the date between 9 pm and 3 am, while the mechanism is changing it.
With 5 ATM water resistance, avoid hot water, showers and baths. Plan a service every five years. On a VK63 chronograph, the battery lasts about three years and is replaced by a watchmaker.
Keep reading
Frequently asked questions
What is a Seiko mod?
A mod watch (from “modding”) is an automatic watch built from parts chosen one by one: case, dial, hands, bezel and strap, around a proven movement. The idea comes from enthusiasts who customised their own watches; when the movement is a Seiko, they call it a “Seiko mod”. At Modus, every watch carries our own brand and our own dial.
Which Seiko movement powers a Modus watch?
A Seiko automatic movement, made in Japan by Seiko Instruments: the Seiko NH35 calibre in most models, the Seiko NH34 in the GMTs, the Seiko NH70 in the skeletons and the Seiko VK63 in the chronographs. The watches are designed and sold by Modus Horlogerie.
Why the Seiko NH35 movement?
The NH35 is a 24-jewel automatic calibre with a date and hacking seconds. It's known for its robustness and it's easy to service: any watchmaker can work on it. It's the best choice for a reliable automatic watch under €400.
Does a mod watch carry another brand's name?
No. A Modus mod watch carries only the Modus Horlogerie name. It can take inspiration from the great watchmaking classics (dive-style, GMT, chronograph), but it never passes itself off as another watch or uses another brand's logo.
Can I build my own mod watch?
Yes. The Modus configurator lets you choose the case, dial, bezel, hands and strap, and add an engraving or your logo, with a live preview. A custom watch costs €349, plus any options you pick.
What about warranty and shipping?
Every watch comes with a 3-year warranty (movement and 5 ATM water resistance). Tracked shipping is free worldwide, with no minimum order, and you have 30 days to change your mind. Outside the European Union, customs duties or local taxes may be charged on delivery.
Is a Seiko mod reliable?
The movement is: the NH35 is mass-produced by Seiko Instruments, well documented, and any watchmaker can service it. The rest depends on the watch: 316L steel case, sapphire crystal, a well-made crown and gaskets, regulation and a warranty. Every Modus watch is covered for 3 years.
What is the difference between the NH35 and the VK63?
The NH35 is automatic: it winds itself with the movement of your wrist and has no battery. The VK63 is a meca-quartz: it runs on a battery (about 3 years) and drives a chronograph, with a seconds hand that sweeps the dial and an instant reset. It is more accurate than an automatic, but it is not automatic. Our INTERVAL and COSMOS watches use the VK63.
How long until I receive my watch?
A catalogue watch ships within 24 to 48 business hours. A watch built in the configurator is prepared to order: allow 9 to 11 days, delivery included.
How do I look after a Seiko mod?
Wear it, or give the crown 20 to 30 turns if it has stopped. Do not set the date between 9 pm and 3 am. Avoid hot water and showers: water resistance is 5 ATM. Plan a service every five years, by a watchmaker or by our after-sales team.
