What Is a Seiko Mod?

The term “Seiko Mod” is widely used within the watch community to describe a custom-built or modified timepiece created using compatible components and movements associated with the Seiko modding ecosystem.

At Modelier Timepieces, each watch is independently assembled and quality-checked using carefully selected components to create distinctive, personalised timepieces.

Our custom-built watches are not official Seiko factory models.

Modelier Timepieces is an independent business and is not affiliated with, authorised by, endorsed by, sponsored by or otherwise officially connected with Seiko Watch Corporation.

Any third-party trademarks referenced on our website are used solely for descriptive, identification or compatibility purposes.

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Built Individually

Each Modelier timepiece is individually assembled rather than mass-produced as a finished factory watch.

Depending on the chosen design, our builds may combine carefully selected components such as:

• watch cases
• custom or compatible dials
• hands
• bezels and bezel inserts
• sapphire crystals
• bracelets and straps
• automatic, mechanical or hybrid chronograph movements

This allows us to create a wide variety of designs and configurations while maintaining the distinctive identity of Modelier Timepieces.

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Powered by Seiko Group / TMI Movements

A key part of many Modelier builds is the movement inside.

We use a selection of movements manufactured by TMI – Time Module, a company within the Seiko Group and an established Japanese watch-movement manufacturer.

Depending on the design and functionality of the watch, Modelier may use the following calibres:

Automatic & Mechanical Movements

NH34 GMT
An automatic GMT movement capable of displaying an additional time zone through a dedicated GMT hand.

NH35 Automatic
One of the most widely used Japanese automatic movements, known for its robust construction, reliability and ease of servicing.

NH36 Day-Date
An automatic movement offering both day and date functionality.

NH38 Open-Heart
An automatic movement designed for open-heart dial configurations, allowing part of the mechanical movement to remain visible through the dial.

NH70 Skeleton
A skeletonised mechanical movement designed to showcase the internal structure and operation of the movement.

NH72 Skeleton
A skeletonised automatic movement offering a distinctive open-worked appearance for more expressive watch designs.

Premium Hybrid Chronograph Movements

For selected chronograph builds, Modelier uses movements from the TMI VK Premium Chronograph series, including:

VK61
VK63
VK64

These movements combine the accuracy and reliability of quartz regulation with mechanical-style chronograph operation.

The VK series is particularly valued for features such as:

• mechanical-style chronograph feel
• responsive pushers
• fast chronograph reset
• sweeping chronograph seconds operation
• quartz-controlled timekeeping accuracy

This combination is often referred to within the watch community as meca-quartz or hybrid chronograph technology.

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Japanese Movement Engineering

The NH and VK movement families have become widely used throughout the independent and custom watch industry because of their combination of reliability, serviceability and proven engineering.

For example, the NH35 automatic movement operates at 21,600 vibrations per hour and offers a manufacturer-rated power reserve of more than approximately 41 hours when fully wound.

As with all mechanical movements, actual timekeeping performance may vary depending on factors such as:

• position
• temperature
• level of winding
• usage
• individual movement tolerances

We therefore avoid claiming an unrealistic fixed daily accuracy figure.

The exact movement fitted to each Modelier watch is clearly stated on the relevant product page.

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Materials & Components

Alongside reliable movements, we focus on materials selected for durability, appearance and everyday use.

Depending on the individual model, specifications may include:

• 316L stainless-steel cases
• sapphire crystal
• ceramic bezel inserts
• stainless-steel bracelets
• selected leather or other straps
• automatic, mechanical or hybrid chronograph movements

Because every Modelier design can have different specifications, customers should refer to the relevant product page for the exact details of each watch.

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Hand-Assembled & Quality Checked

Every Modelier timepiece is assembled individually and inspected before shipment.

Our quality-control process may include checks of:

• movement operation
• timekeeping
• hand alignment
• crown and stem functionality
• chronograph functionality where applicable
• visual alignment
• exterior condition
• component fitment
• packaging

Only after completing the applicable checks is the watch approved for shipment.

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More Than a Standard Factory Watch

The appeal of a custom-built watch is the freedom to create something different from a conventional mass-produced model.

Modelier combines established movement technology with carefully selected components and distinctive designs to create watches with their own character.

Customers can choose from our existing collections or, where available, explore more personalised combinations through our custom services.

The result is an independently assembled Modelier Timepiece designed for customers looking for something more personal and distinctive.

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Independent Brand Disclaimer

Modelier Timepieces is an independent watch business.

References to Seiko®, TMI, Time Module or other third-party manufacturers are made solely to accurately identify the origin, type or compatibility of components used in our watches.

Modelier Timepieces is not affiliated with, authorised by, sponsored by or endorsed by Seiko Watch Corporation or any other third-party watch manufacturer unless expressly stated otherwise.

Third-party trademarks remain the property of their respective owners.