Casio G-Shock Master of G GR-B300-1AER

Introducing a new addition to the G-SHOCK Master of G collection: the GRAVITYMASTER GR-B300, an aviation-inspired professional watch designed to perform in even the harshest environments. The GR-B300 features a Carbon Core Guard construction for maximum durability. The carbon fiber-reinforced resin case and bezel design, inspired by next-generation aircraft, blend together in a bold and powerful form. See the world through a pilot's eyes with the flight log memory function to record your current location and time, and with dual time zone displays. Simply tap the app to instantly switch between home time and local time, a convenient feature when traveling abroad. Large indices and a stainless steel bezel add to the spaciousness of the dial, ensuring improved visibility—essential for pilots whose work requires quick and intuitive time reading. The black and white color combination evokes the look of a cockpit instrument panel.

Technical Specifications

📦 Basic information

• Case Dimensions (H × W × D) : 59 × 54.7 × 15.7 mm

• Weight : 71 g

• Materials :

  • Case and bezel in bio-carbon and bio-resin

  • Adjustable bio-resin strap (145 to 215 mm)

• Structure :

  • Shock resistant

  • Carbon Core Guard Structure

• Water resistance : Up to 20 bar

⏰ Time functions

• Automatic time via Bluetooth (connection with smartphone)

• World Time (up to 300 cities)

• Dual time zone with quick change

• Accuracy : ±15 seconds/month (without connection)

• Calendar : automatic until the year 2099

• Date display : day of the month

• Time indication :

  • Analog: 3 hands (hours, minutes, seconds)

  • 3 dials: second time zone, 24h, date

📱 Connectivity

• Bluetooth® (Mobile Link)

• Compatible with the CASIO WATCHES app

• App Features:

  • Automatic time adjustment

  • Flight log

  • Find phone

  • Quick setup

🔋 Power supply and duration

• Tough Solar (solar energy)

• Battery life:

  • ~5 months (normal use, without light)

  • ~18 months (in energy saving and dark mode)

• Battery level indicator

• Energy saving : the hands stop in the dark

⏱ Chronometric functions

• Stopwatch : 1 second, up to 24 hours

  • Mode: elapsed time, split time

• Countdown timer : 1 minute to 24 hours

  • Settings in 1 minute or 1 hour increments

• Daily sound reminder

• Time signal

💡 Lighting and visibility

• White LED light (Super Illuminator)

• Neobrite on the hands

🛡 Aesthetics and external details

• Glass : mineral

• Crown : screw

• Bezel : with black IP treatment