Casio G-Shock GST-B400 Watches


Quick Content Guide

  1. Japanese approaches to Tough and Functional Watches in GST-B400! *the most distinctive features in details
  2. General information about the watch *year of first release, model range etc.
  3. GST-B400 Usage Patterns *what the watch is usually meant for
  4. Feedback from Users and Experts *anonymous from different sources
  5. GST-B400 Model Range *in different colors and bands
  6. GST-B400 Limited Editions *unique style, materials, and price
  7. The most distinctive specs *from our Editorial point of view
  8. Other G-Shock GST Watches *similar by price and functions but different by cases
  9. Official GST-B400 Video *only from Casio Company
  10. Official GST-B400 Specs *all details and for base version GST-B400-1A
  11. GST-B400 Comparison Table *with similar G-Shock Watches

Enjoy Japanese approaches to Tough and Functional Watches!

Tough Solar & Improved Readability. The GST-B400 is powered by G-SHOCK Tough Solar power system, charged by both real and artificial light sources. To ensure great readability, as well, a dial indicator at the 9 o’clock position display the mode, battery level and more.

Stylish & Sophisticated looks. The watch features a stainless-steel bezel in a sophisticated new shape. Attention to detail and material quality are paramount for the G-STEEL, featuring unique finishing techniques like hairline, mirror and polishing, highlighting an impressive array of surface textures that captivate the eye from every angle.

Metal Band with Double Slide Lever. This allows quick and easy change of the bands.

Slimness & Energy-Saving Module. Optimised, high-density mounting of the circuit board structure has made it possible to slim the module of the new GST-B400. A substantial reduction in power consumption was also achieved by reducing the number of watch hands to two and adopting a low-power Bluetooth® system.

Shock Resistant. Shock-resistant construction protects against impact and vibration.

G-SHOCK CONNECTED App. Connection with a phone requires installation of the G-SHOCK CONNECTED App on the phone.

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General Information

Price320$ 
*average Amazon Price, we may earn commission from purchases
Year of first Release2021
Module Number5657 / Manual
Model RangeG-STEEL (G-Steel are refined watches and combine high-quality materials with G-Shock’s standard of toughness. Its layered guard structure boasts a double-layer bezel construction of stainless steel and resin or resin and fine resin which delivers the hard, sleek beauty of metal while retaining the impact absorption of resin.)
Battery TypeSolar (G-Shock Batteries)
Other Divisions the GST-B400 belongs to: *you may find all watches of the division by clicking on the linkG-Shock Ana-Digi
G-Shock Bluetooth
G-Shock Solar
G-Shock 2021

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GST-B400 Usage Patterns *what the watch is usually meant for

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Feedback from Users *accumulated information from our own comments and emails, forum threads, socials, reviews, etc.

PROs
+ looks a lot more expensive than it is
+ the strap looks very comfortable
+ fits just fine and the lightweight is a plus
+ they fixed the battery indicator from the gst-b100 so it’s easier to check the battery level
+ they slimmed down the watch

CONs
– too few color/ stainless steel variants with straps without negative displays
– no backlight movement detector and timer
– no lume
– at that price it should DEFINITELY have a sapphire glass
– they removed a very useful second hand

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GST-B400 Model Range *may be updated

*You may find updated information about colors on our G-Shock 2021 New Releases page →

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GST-B400 Limited Editions *unique style, materials, and price

GST-B400BD-1A2

The Listing of All G-Shock GST-B400 Limited Watches → *with detailed description about the style

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The most distinctive specs of GST-B400 *Editorial
The Slimmest-Ever G-STEEL as for 2021 (it features a new, improved module built to deliver slimness)
Beautiful battery level indicator at 9 o’clock (displays the mode, battery level and more)
Vapor deposition-treated dials (for highly chromogenic and distinctive coloration)
Tough Solar (CASIO’s original solar-charging system converts not only sunlight but also light from fluorescent lamps and other sources into power)
G-SHOCK Connected App (you may manage all watch settings through your phone)

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Other G-Shock GST Watches *similar by price and functions but different by cases

These are not all G-Shock GST Series. Here is a list of All G-Shock GST Watches →


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Official GST-B400 Video

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Official Marketing Focus from Casio

Introducing new color variations to the lineup of slim G-STEEL GST-B400 models with new, improved designs made possible by a thin module and carbon core guard structure. There is a standard model in this lineup, the GST-B400 with silver color face and resin band.
The GST-B400 is made possible by even further miniaturization of its parts and thinning of its modules without sacrificing any Bluetooth or solar function. Power consumption has also been significantly reduced.


Official GST-B400 Specs / Features *for base version GST-B400-1A

  • Case / bezel material: Resin / Stainless steel
  • Resin Band
  • Mineral Glass
  • Neobrite
  • Shock Resistant
  • Carbon Core Guard structure
  • 200-meter water resistance
  • Shock resistant (G-SHOCK)
  • Tough Solar (Solar powered)
  • Double LED light
    LED light for the face (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds), afterglow)
    LED backlight for the digital display (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds),afterglow)
  • Mobile link (Wireless linking using Bluetooth®)
  • Hand shift feature (Hands move out of the way to provide an unobstructed view of digital display contents)
  • World time
    38 time zones (38 cities + coordinated universal time), city code display, city name display, daylight saving on/off, auto summer time (DST) switching, Home city/World time city swapping
  • 1/100-second stopwatch
    Measuring capacity: 00’00”00~59’59”99 (for the first 60 minutes)
    1:00’00~23:59’59 (after 60 minutes)
    Measuring unit: 1/100 second (for the first 60 minutes)
    1 second (after 60 minutes)
    Measuring modes: Elapsed time, lap/split time
  • Countdown timer
    Measuring unit: 1 second
    Countdown range: 60 minutes
    Countdown start time setting range: 1 second to 60 minutes (1-second increments and 1-minute increments)
  • 5 daily alarms
  • Hourly time signal
  • Battery level indicator
  • Power Saving (display goes blank to save power when the watch is left in the dark)
  • Full auto-calendar (to year 2099)
  • 12/24-hour format
  • Button operation tone on/off
  • Date/month display swapping
  • Day display (days of the week selectable in six languages)
  • Regular timekeeping
    Analog: 2 hands (Hour, minute (hand moves every 20 seconds))
    1 dial (battery level, mode)
    Digital: Hour, minute, second, pm, month, date, day
  • Accuracy: ±15 seconds per month (with no mobile link function)
  • Approx. battery operating time:
    7 months on rechargeable battery (operation period with normal use without exposure to light after charge)
    18 months on rechargeable battery (operation period when stored in total darkness with the power save function on after full charge)
  • Size of case : 46.6×49.6×12.9mm
  • Total weight : 80g

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GST-B400 Comparison Table with similar G-Shock Watches

GST-B400

Price (Amazon)

Year of first Release

2021

2019

Accuracy

Bluetooth (via phone app)

Bluetooth (via phone app)

Bluetooth (via phone app)

SmartWatch Features

G-SHOCK Connected App

G-SHOCK Connected App

G-SHOCK Connected App

Light

Neobrite and Double LED light

Neobrite and Double LED light (Full auto LED light, Super illuminator)

Neobrite and Double LED light (Full auto LED light, Super illuminator)

Alarm

5 daily alarms

5 multi-function alarms (with daily, 1 time, schedule)

5 multi-function alarms (with daily, 1 time, schedule)

Timer

Measuring unit: 1 second
Countdown range: 60 minutes
Countdown start time setting range: 1 second to 60 minutes (1-second increments and 1-minute increments)

Measuring unit: 1/10 second
Countdown range: 24 hours
Countdown start time setting range: 1 second to 24 hours (1-second increments, 1-minute increments and 1-hour increments)

Measuring unit: 1/10 second
Countdown range: 24 hours
Countdown start time setting range: 1 second to 24 hours (1-second increments, 1-minute increments and 1-hour increments)

Stopwatch

1/100-second stopwatch
Measuring capacity: 00’00”00~59’59”99 (for the first 60 minutes)
1:00’00~23:59’59 (after 60 minutes)
Measuring unit: 1/100 second (for the first 60 minutes)
1 second (after 60 minutes)
Measuring modes: Elapsed time, lap/split time

1/1000-second stopwatch
Measuring capacity:
00'00''000~59'59''999 (for the first 60 minutes)
1:00'00''0~23:59'59''9 (after 60 minutes)
Measuring unit:
1/1000 second (for the first 60 minutes)
1/10 second (after 60 minutes)
Measuring modes: Elapsed time, split time

1/1000-second stopwatch
Measuring capacity:
00'00''000~59'59''999 (for the first 60 minutes)
1:00'00''0~23:59'59''9 (after 60 minutes)
Measuring unit:
1/1000 second (for the first 60 minutes)
1/10 second (after 60 minutes)
Measuring modes: Elapsed time, split time

Hourly Time Signal

Yes

Yes

Yes

World Time

38 time zones (38 cities + coordinated universal time), city code display, city name display, daylight saving on/off, auto summer time (DST) switching, Home city/World time city swapping

39 time zones* (39 cities + coordinated universal time), daylight saving on/off, auto summer time (DST) switching, Home city/World time city swapping

39 time zones* (39 cities + coordinated universal time), daylight saving on/off, auto summer time (DST) switching, Home city/World time city swapping

Multi Day Format

Yes

Yes

No

Multi Language Day

Yes

Yes

No

Second Hand

Yes

Yes

Yes

Case / bezel material

Resin / Stainless steel

Resin / Stainless steel

Carbon / Stainless steel

Glass

Mineral Glass

Mineral Glass

Mineral Glass

Battery

Solar powered

Solar powered CTL1616

Solar powered CTL1616

Size (mm) *we consider 48.9×42.8×13.4 to be a traditional watch size (as in DW-5600). So you are to compare how far or close the watch is to this size

46.6×49.6×12.9

51×50×15.5

53.3×49.2×14.5

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Recent News about GST-B400 

All Casio GST-B400 News →


You ask, we answer…

How does Tough Solar in GST-B400 work?

It’s CASIO’s original solar-charging system that converts not only sunlight but also light from fluorescent lamps and other sources into power.

What are Vapor deposition-treated dials in GST-B400?

They are used for highly chromogenic and distinctive coloration.

What does G-SHOCK Connected App in GST-B400 do?

You may manage all watch settings through your phone.


Not sure about GST-B400? There are more G-Shocks!

Back to All G-Shock Models →