Modus Watchmaking Workshop: the art of the Seiko Mod assembled in France

Welcome to the Modus Horlogerie workshop, a space where horological precision meets personalisation.
We are a French micro-brand specializing in Seiko Mod , that is, the customization of mechanical watches based on authentic movements supplied by Seiko Instruments Inc. (SII) .

We are not affiliated with any watch brand.
We are an independent workshop that assembles, adjusts and checks each watch by hand in France .

A French micro-brand dedicated to the Seiko Mod

Modus Horlogerie is an independent brand registered in France, specializing in watches:

• automatic

• customizable

• built around Seiko Instruments Inc. (SII) calibers

• assembled entirely by hand in our French workshop

We offer:

• ready-to-ship models, inspired by iconic designs (Submariner, Royal Oak, Nautilus, Datejust, Daytona, GMT, Speedmaster…);

• as well as fully personalized watches , created via our configurator.

Each watch benefits from premium materials:

• sapphire glass

• anti-reflective coating

• 316L stainless steel

• ceramic glasses depending on the models

• “solid end-links” bracelets

• Durable seals and screwed or clipped bases, depending on the model.

And we systematically offer:

• 3-year warranty

• 30-day return policy

• free delivery

• certificate of authenticity

• premium leather box

The Seiko Mod: legal and transparent watch customization

Seiko Mod (or Seiko modding) consists of customizing a watch built around an authentic movement from Seiko Instruments Inc. (SII) .

This is a legal and widely recognized practice in the watchmaking community, comparable to car tuning.
You don't copy a brand:
We customize , improve , and modify with compatible components.

At Modus Horlogerie:

• The movements are sourced from Seiko Instruments Inc. (SII).

• All other components (cases, dials, hands, bezels, straps, etc.) are new , compatible , and without any protected trademarks.

• We do not manufacture copies of existing watches.

• We do not reproduce third-party brand logos.

• We remain 100% transparent about the origin of the components

Our workshop therefore assembles modded watches , based on reliable and authentic mechanics, within a completely legal framework.

Inside our French watchmaking workshop

Each watch follows a strict process consisting of several essential steps.

1. Component selection and control

Upon receipt, we inspect:

• CNC machined housings made of 316L steel

• ceramic glasses

• classic dials, sunburst, arabic, open-heart or skeleton

• compatible needles

• sapphire lenses

• steel or vulcanized rubber bracelets

• gaskets, crowns and bottoms of gearbox

Any component that does not meet our standards is excluded.

2. Preparation and cleaning

Before assembly:

• Sensitive items are cleaned in a controlled environment

• the seals are checked

• The surfaces are protected to prevent dust and micro-scratches.

The goal: to obtain a clean, neat, durable assembly.

3. Seiko Instruments Inc. (SII) movements

We work exclusively with mechanical or meca-quartz movements from Seiko Instruments Inc. , including:

• NH35 : Automatic 3-hand + date

• NH34 GMT : Dual time zone

• NH38 : open-heart

• NH70 / NH72 : high-end skeleton

• VK63 : mechanical quartz chronograph

Each movement is:

• tested on chronocomparator

• adjusted for optimal accuracy

• visually inspected

• checked in amplitude and in operation

4. Hand assembly

The assembly is done entirely by hand:

• dial installation

• precise placement of the needles

• movement casing

• Sapphire crystal installation

• mounting the scope

• closing the fund

• bracelet installation

Each step is carried out with specialized watchmaking tools and meticulous care.

5. Strict quality control

Before final validation, we perform the following:

• inspection under magnification

• amplitude and drift test

• power reserve check

• compression and seal control

• bracelet adjustment if necessary

Our internal checklist includes 15+ checkpoints .

Premium materials in all our watches

We use high-end materials:

• flat or double-domed sapphire crystal

• anti-reflective coating

• 316L stainless steel

• ceramic glasses

• Luminova on hands and indexes

• solid link bracelets

• transparent backgrounds according to models

• high precision CNC housings

These choices guarantee a watch that is durable, reliable, comfortable to wear and suitable for everyday use.

Customization: Create your own modded watch

With our configurator, you can create a completely unique watch:

1. choose the case style (Submariner, Royal Oak, Nautilus, Datejust, Daytona, GMT…)

2. select the dial

3. choose the needles

4. choose the glasses

5. choose the bracelet

6. validate and let our workshop assemble your project

Each personalized watch is:

• hand-assembled in France

• individually adjusted

• tested and inspected

• delivered with warranty and certificate

What you receive with a Modus Horlogerie watch

Each order includes:

• a premium leather box

• a bracelet adjustment kit

• a 3-year warranty

• a certificate of authenticity

• free delivery

• a responsive support service based in France

Why choose a French Seiko Mod workshop?

Modus Horlogerie is:

• an independent workshop

• Modified watches built around authentic Seiko Instruments Inc. movements

• hand-assembled in France

• strict quality control

• responsive human support

• complete transparency regarding the materials and legality of the Seiko Mod

Conclusion

Modus Horlogerie is a French watchmaking workshop specializing in the customization of mechanical watches based on authentic Seiko Instruments Inc. (SII) movements.
We are not affiliated with any brand, and we work within a clear legal framework: authentic movements, compatible components, no protected logos.

Our mission: to offer premium modded watches, assembled in France, customizable, durable, and accessible.