• G-Shock
  • Item no. GST-B400X-1A4
  • $400.00
    • Discontinued

G-STEEL G-CARBON SLIM

G-STEEL with Bluetooth® that lets them connect with a smartphone at the press of a button. See more

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Item No. : GST-B400BB-1A
Gender : Men’s
Color : Black
Material : Black IP Resin Steel
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Item No. : GST-B400GB-1A9
Gender : Men’s
Color : Black Gold
Material : Gold IP Resin Steel
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Item No. : GST-B400CD-1A3C
Gender : Men’s
Color : Green Silver
Material : Green IP Steel
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Item No. : GST-B400MV-5ACR
Gender : Men’s
Color : Brown Copper
Material : Copper IP Resin Steel
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Item No. : GST-B400X-1A4
Gender : Men’s
Color : Black
Material : Carbon-Fiber Resin Steel
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Item No. : GST-B400BD-1A2
Gender : Men’s
Color : Black Blue
Material : Black IP Steel
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Item No. : GST-B400D-1A
Gender : Men’s
Color : Black Silver
Material : Steel
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Item No. : GST-B400-1A
Gender : Men’s
Color : Black Silver
Material : Resin Steel
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GSTB400X-1A4

Introducing the GSTB400X-1A4, the newest model of the slim G-STEEL GSTB400 series. The GSTB400X-1A4 sports a lightweight yet tough carbon bezel, which is a combination of carbon fiber reinforced resin and carbon sheets. This stylishly stealthy timepiece is styled with a black resin band and a black IP case with red accents.

The GSTB400 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.

In addition, the carbon core guard structure of this model helps to make it the thinnest of the G-STEEL Series (as of Apr 2021) while maintaining a high level of impact resistance. The thickness from the back cover to the bezel top is only 12.9 mm, which is more than one millimeter less than the GSTB100 model. In terms of design, the number of button guards has been reduced as much as possible, enabling the use of large stainless steel buttons that are slim yet easy to operate.

A THINNER AND MORE COMPACT G-STEEL GST-B400

Slimmest-Ever G-STEEL

Presenting a stylishly designed look, the new GST-B400 watches deliver the slimmest case of any G-STEEL yet, at just 12.9 mm. They feature a new, improved module built to deliver slimness.

DESIGN

Independent Bezel

The watch features a stainless-steel bezel in a sophisticated shape. With attention to detail, even different facets of the same parts are uniquely finished using different types of finishing technique: hairline, mirror finishes and polishing process. This shows off an impressive array of metallic surface textures that captivate the eye from every angle.

Vapour Deposition Treated Dial

A power-saving module enables the use of an opaquer dial, and highly chromogenic dial colouration is achieved with multilayer vapour deposition. Vapour deposition is applied to the iconic G-STEEL dial indicator and bridge parts as well as parts of the face design, proving the meticulous care taken through the very last detail.
*Above description applies to the GST-B400AD.

Improved Readability

To ensure great readability, as well, a dial indicator at the 9 o’clock position display the mode, battery level and more.

Metal Band with Double Slide Lever

This allows quick and easy change ofthe bands.

TECHNOLOGY

Slimness & Energy-saving Module

Optimized, high-density mounting of the circuit board structure made it possible to slim the module. 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. The ability to solar charge with an opaquer dial allowed for a high degree of freedom in dial design.

 

Carbon Core Guard Structure

Offering strength, lightness and excellent weather resistance, a carbon fibre-reinforced resin case protects the module. Additionally, buffering components made of resin mounted between the upper and lower bezels help absorb external shocks. At just 12.9mm, this is the slimmest case in the G-STEEL line. The newly developed form of the button guards makes it possible to offer generously sized stainless-steel buttons even in this extra-slim design.

G-SHOCK Connected

Smartphone App (Android & iPhone)

* App screens shown here may differ from actual screens, since the app is currently under development.

– Automatic time adjustment*

– World Time for over 300 cities*

– Alarm/Timer setting

– Phone Finder

* Updating of internal data according to the latest time zone/ daylight saving time information

* The Bluetooth® wordmark and logo are registered trademarks of Bluetooth SIG, Inc. and any use of these marks by Casio Computer Co., Ltd. is under license.

* Apple, Apple logo and iPhone are trademark of Apple Inc. registered in the United States and other countries. App Store is a service mark of Apple Inc.

* IOS is a trademark or registered trademark of Cisco Systems, Inc. registered in the U.S.

* Google Play and the Google Play logo are trademarks of Google Inc.

* All other company and product names are trademarks or registered trademarks of their respective owners.

* List of Countries and Geographic Areas where Product Conforms to Radio Laws or Has Been Approved.

SMARTPHONE LINK

Links with a smartphone for more accurate timekeeping and access to a host of mobile link functions.

SHOCK RESISTANT

Shock-resistant construction protects against impact and vibration.

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

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

 

  • LED Light (Super Illuminator)

    A light emitting diode is used to illuminate the face/display. Super Illuminator uses high-brightness LED for easier reading

  • Dual Time

    Simultaneous display of the current time in two different time zones

  • Daily Alarm, Hourly Time Signal

    The daily alarm sounds each day at the time you set. The value indicates how many alarms are available. The hourly time signal causes the watch to beep every hour on the hour

  • Stopwatch (1/100 24HR)

    Accurate measurement of elapsed time with the touch of a button. The fraction indicates the unit of measurement, while the time figure indicates the maximum time measurement

  • Timer (24H)

    Counts down from a start time specified by you. The value indicates the number of timers available, while the time figure indicates the maximum starting time. “REPEAT” indicates Auto Repeat, which automatically restarts timing at the end of each countdown

  • Beeper Alarm

    Beeper tone alarm sounds at the time you set

  • Full Auto-Calendar

    Allowances are made automatically for months of different lengths, including leap year

  • 12/24-Hour Timekeeping

    Times can be displayed in either 12-hour or 24-hour format

  • Battery Level Indicator

    Indicator shows the current battery level

  • Shock Resistant

    Shock-resistant construction protects against impact and vibration

  • Water Resistant (20 BAR)

    The “BAR” value indicates the number of atmospheres to which water resistance is ensured. 20 BAR means water resistance to 20 atmospheres. Watches marked “200m” have the same water resistance as 20 BAR watches

  • Mineral Glass

    Hard glass resists scratching

  • Crown

    Screw-Lock

  • Bezel

    Carbon

  • Band

    Black Resin

  • Case / bezel material: Carbon / 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: 74g
  • Module: 5675
  • UPC: 889232308753

Carbon Core Guard structure logo

Bluetooth<sup>™</sup> logo

Smartphone App

Get It On Google Play

Smartphone App

Download on the App Store

Operation Guide (HTML)

Module No. 5657

Operation Guide (PDF)
CASIO SUPPORT ^
CASIO WATCH MANUAL ARCHIVES ^

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