Casio G-Shock Master of G GR-B300-1A4ER

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 scheme evokes the look of a cockpit instrument panel. The main resin components used for the case, bezel, and strap are made from bio-based resin, a material designed to help reduce environmental impact.

Technical Specifications

Basic information

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

• Weight : 71 g

• Case and bezel material : Bio-based carbon / Bio-based resin

• Strap : Bio-based resin strap, adjustable from 145 to 215 mm

• Construction : Impact Resistant, Carbon Core Guard

• Water resistance : Up to 20 bar

Power and Battery Life

• Power supply : Tough Solar (solar energy)

• Battery life :

  • 5 months (normal use without exposure to light after one charge)

  • 18 months (with energy saving and stored in the dark)

• Battery status display : Battery level indicator

• Power saving function : Hands stop in the dark to conserve energy

Time functions

• Bluetooth : Automatic connection with smartphone to adjust the time

• World Time : Setting of approximately 300 cities

• Dual Time : Quickly switch between time zones

• Accuracy : ±15 seconds per month (without Mobile Link)

• Calendar : Automatic until 2099

• Date display : Day of the month

• Regular time : Analog with 3 hands (hours, minutes, seconds) and 3 dials (second time zone, 24 hours, day of the month)

Special Features

• Stopwatch : Measures up to 23:59'59 (1 second)

  • Mode: Elapsed time, Split time

• Timer : Countdown timer with 1 second measurement unit

  • Setting range: 1 minute to 24 hours

• Sound Reminder : Daily Sound

• Time Signal : Regular time warning

Visibility and Light

• Light : White LED (Super Illuminator)

• Luminescence : Light color

• Neobrite : For improved visibility in the dark

Smartphone and App Connection

• Smartphone connection function via Mobile Link (Bluetooth®)

• CASIO WATCHES App :

  • Automatic clock adjustment

  • Flight log

  • Find phone

External

• Glass : Mineral

• Crown : Screw-down

• Bezel : Black IP treatment

• Impact Resistance : Carbon Core Guard Structure