CUSTOM GMTEIKO EDITION GMT COKE MOD - Monomods
CUSTOM GMTEIKO EDITION GMT COKE MOD - Monomods
CUSTOM GMTEIKO EDITION GMT COKE MOD - Monomods
CUSTOM GMTEIKO EDITION GMT COKE MOD - Monomods

4.8 based on 811+ reviews

CUSTOM GMTEIKO EDITION GMT COKE MOD

Sale price$379.95 USD Regular price$539.95 USD
Save $160.00

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Estimated assembly: 3–5 business days
Hand assembled to order Genuine Japanese movement Individually inspected
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Description

The Seiko Mod GMT Coke Edition blends classic style with modern performance, embodying the spirit of adventure and precision. Its 40mm 316L stainless steel case and bracelet frame a bold red and black ceramic bezel, reflecting the essence of timeless travel design. The black dial, enhanced with luminous markers and hands, ensures perfect legibility in any environment.

Powered by the reliable NH34 automatic GMT movement, it provides accurate dual-time tracking for global travelers. A sapphire crystal with anti-reflective coating protects the dial, while the screw-down crown and solid construction ensure lasting durability. With adjustable sizing and your choice of crystal or steel case back, the GMT Coke Edition unites craftsmanship, functionality, and refined sophistication—built for those who live without boundaries.

Specifications
Model Name Mod GMT Coke Edition
Diameter 40mm (excluding crown)
Thickness 12mm
Movement Seiko NH34 Automatic Movement
Glass Sapphire, anti-scratch with anti-reflective treatment
Luminova Yes
Case Material 316L Stainless Steel
Crown Screwed
Bezel Ceramic (Red & Black “Coke” style)
Bracelet 316L Stainless Steel with Security Clasp
Lug Width 20mm
Wrist Size 14.5cm – 22cm (adjustable)
Case Back Standard Crystal (open display) / Steel (closed back)
Water Resistance 3 ATM
Functions Dual Time (GMT)
2 Years Warranty

Every watch includes a 2-year warranty against manufacturing defects.
Built for long-term reliability, backed by real support.

Return Policy

30-day money-back guarantee.
Return your watch within 30 days if it’s not right for you.

Custom Logo Information

Personalize your watch with your own logo on the dial.

  • Select the Custom Logo variant — an upload field will appear.
  • Upload your logo in PNG or JPEG format.
  • Trademarked or copyrighted logos belonging to third parties are not allowed.
  • We’ll send you a digital preview for approval before production starts.
  • For optimal results, we recommend a high-resolution file with a white background.
What's Included

Every order includes everything you need to enjoy your timepiece from day one:

- Luxury presentation box
- Warranty card
- Mini adjustment toolkit

Seiko TMI NH34 manual

Automatic GMT

A reliable Japanese automatic GMT movement that allows you to track a second time zone using an independently adjustable 24-hour GMT hand. The NH34 is ideal for travelers and GMT-style watches, combining dependable automatic performance with practical dual-time functionality.

The TMI NH34 is an automatic mechanical GMT movement developed by TMI (Time Module Inc., part of the Seiko Group). Based on the trusted NH series architecture, it features manual winding, hacking seconds, and a dedicated 24-hour GMT hand for tracking a second time zone.

Specification

Details

Manufacturer

TMI (Seiko Group)

Caliber

NH34

Movement Type

Automatic GMT with Manual Winding

Functions

Hours, Minutes, Seconds, 24-Hour GMT Hand, Date

Jewels

24 Jewels

Beat Rate

21,600 BPH (3 Hz)

Power Reserve

Approx. 41 Hours

Diameter

27.40 mm

Height

5.32 mm

Accuracy

-20 / +40 seconds per day

Hacking Seconds

Yes

Country of Origin

Japan or Malaysia


Operating Instructions

Automatic Winding

The NH34 automatically winds itself through the natural movement of your wrist while worn.

Manual Winding

If the watch has stopped:

  • Turn the crown clockwise approximately 55 times to fully wind the mainspring.

  • The watch will continue winding automatically while being worn.

Setting the Time

  1. Pull the crown to the second click.

  2. Turn the crown until the correct local time is displayed.

  3. The second hand stops while setting the time for precise synchronization.

  4. Push the crown back to the normal position.

Setting the GMT Hand & Date

  1. Pull the crown to the first click.

  2. Turn the crown in one direction to adjust the 24-hour GMT hand.

  3. Turn the crown in the opposite direction to adjust the date.

  4. Push the crown back once finished.

Important: Do not change the date between 9:00 PM and 4:00 AM, as the calendar mechanism may be engaged.


Using the GMT Function

The additional 24-hour GMT hand allows you to track a second time zone.

  • Set the main hour and minute hands to your local time.

  • Adjust the GMT hand to the second time zone you wish to monitor.

  • Read the GMT hand against the 24-hour bezel or chapter ring to distinguish between AM and PM.

This function is ideal for travelers, business professionals, and anyone communicating across different time zones.


Care & Maintenance

  • Wear the watch regularly to keep the movement wound.

  • If not worn for several days, manually wind before use.

  • Avoid strong magnetic fields and severe impacts.

  • Keep the crown fully pushed in (or screwed down if applicable).

  • Professional servicing is recommended every 5–7 years, depending on usage and environmental conditions.


Why Choose the NH34?

  • Genuine Japanese automatic GMT movement

  • Tracks a second time zone with a dedicated 24-hour GMT hand

  • Manual winding capability

  • Hacking seconds for precise time setting

  • Approximately 41-hour power reserve

  • Durable and reliable NH-series architecture

  • Ideal for travel and everyday use

The TMI NH34 combines the trusted reliability of the NH series with the practicality of a GMT complication, making it an excellent choice for travelers and watch enthusiasts who want to monitor multiple time zones with ease.

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Your watch is made using carefully selected premium materials and handcrafted Japanese craftsmanship.

Discover the difference

Sapphire Crystal

Sapphire crystal is used for one simple reason: long-term clarity.
It resists everyday scratches and wear, so the watch keeps its appearance without needing extra care or concern.

STORE REVIEWS

Rated 4.8 / 5 based on 811+ reviews across all channels. Showing our top reviews.

4.8

5 star
92%
4 star
8%
3 star
0%
2 star
0%
1 star
0%

Sean M.

Verified ·

Came in a sturdy case with a 2-year warranty card inside. Packaging felt premium, and the sapphire glass looks crystal clear—amazing first impression.

Seikosub Marine Shadow

Seikosub Marine Shadow

John D.

Verified ·

Arrived faster than expected and perfectly packaged. The domed glass gives a beautiful vintage vibe, thanks!

Seikosub Milsub Nato

Seikosub Milsub Nato

Natan R.

Verified ·

Solid build, vintage diver look, and smooth automatic movement—feels pretty premium on the wrist.

Scubamaster 58

Scubamaster 58

Michael T.

Verified ·

The presidential bracelet feels super comfortable and solid. Sapphire glass is spotless, and packaging with the warranty card was a great addition.

Seikodate Champagne

Seikodate Champagne

Lisandro K.

Verified ·

Perfect blue tones and great detailing. Shipping was fast, and the watch came well-packed with a warranty card included.

Speedseiko Blue

Speedseiko Blue

David P.

Verified ·

Really like the clean edges and smooth finish on this watch. The brushed steel case looks sharp, and the open-heart dial adds a nice touch. Feels well-built and comfortable on the wrist.

Nautiko Emerald

Nautiko Emerald

Monty S.

Verified ·

Fantastic quality and great attention to detail. It’s easily my new favorite watch. Shipping was fast, packaging was secure, and I’ll definitely be adding more to my collection.

Seitona Bumble Bee

Seitona Bumble Bee

Robert L.

Verified ·

Best purchase I've made in a while. The quality is outstanding and worth every penny.

Nautiko Open Heart

Nautiko Open Heart

George L.

Verified ·

The watch arrived spotless—Feels sturdy on the wrist, and the sapphire glass stays perfectly clear.

Seikodate Imperial

Seikodate Imperial

Chris B.

Verified ·

Superb quality and excellent customer service. This is my favorite MOD store for sure! Love the open back case too.

Nautiko Open Back Case

Nautiko Open Back Case

Joey D.

Verified ·

Exceeded my expectations. The details stand out and it feels premium without being over the top. Delivery was smooth and on time. I’ll be ordering again.

Seitona Bumble Bee

Seitona Bumble Bee

Sandro L.

Verified ·

Came well packed and protected. The watch has a really nice weight to it and the finishing is clean. No complaints at all.

Seikojust Champagne

Seikojust Champagne

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What you can rely on
MONOMODS
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Trusted by thousands of customers worldwide
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Japanese movements, chosen for reliability
Warranty-backed support you can rely on

FAQ

A Seiko mod is a custom watch built around a reliable Japanese Seiko movement, combined with carefully selected aftermarket components.

At MONOMODS, each watch is hand-assembled using proven automatic or hybrid movements, premium materials, and transparent construction, giving you the freedom to enjoy refined designs without counterfeit products.

The goal is simple:
Luxury-inspired design, built honestly, and made accessible without shortcuts.

Each watch is assembled to order, ensuring proper fit, performance, and quality.

Here’s what to expect:

  • Assembly & Quality inspection:  3–5 days
  • Shipping: 5–12 days

Once assembly is complete, you’ll receive your track & trace details by email.

Delivery times may vary slightly depending on destination, but you’ll always know where your watch is.

Yes.

  • Shipping is free
  • Import duties and customs fees are included in the price

There are no surprise charges when your watch arrives.
What you see at checkout is what you pay, simple and transparent.

Yes, personalization is at the heart of what we do.

You can customize:

  • Case
  • Dial
  • Hands
  • Bracelet
  • Logo or initials

If you’d like help designing a fully personalized watch, contact us via email or live chat.

We’ll guide you through the process step by step.

Yes.

If you’d like a watch with your own logo, you can contact us by email or live chat and share your logo along with the watch model you prefer.
We’ll create a design mockup for your approval first.

Once you’ve approved the design, we’ll begin assembling your watch.