Whatever you’re doing, wherever you are — the G-SHOCK Master of G line has your back.

For total support in the harshest environments, this GRAVITYMASTER watch delivers peak performance in punishing conditions in air. It features bold black to exude toughness and a band in the same bright yellow used for emergency rescues and safety signs. This innovative design is a sure fit for the world of professionals involved in rescue efforts and other critical missions.

The organic form of the GRAVITYMASTER GR-B300RY is inspired by next-generation aircraft and rendered with a seamless exterior design. The Carbon Core Guard structure and wide 3D face deliver durability, readability, and a comfortable fit. Enjoy all the practical functions as well, including dual-time simultaneously showing the time in two cities, a flight log memory function for recording routes traveled, and more.

This tough watch delivers what you need to make quick decisions and take decisive action in the harshest of environments.

• Case size (L× W× H): 59 × 54.7 × 15.7 mm
  
• Weight: 71 g
  
• Case and bezel material: Bio-based Carbon / Bio-based resin / Stainless steel
  
• Band: Bio-based resin band
  
• Construction: Shock Resistant, Carbon Core Guard structure
  
• Water resistance: 200-meter water resistance
  
• Time adjustment: Bluetooth: Connects to a smartphone and automatically adjusts the time
  
• Power supply and battery life: Tough Solar (Solar powered)
  
• Smartphone Link feature: Mobile link (Wireless linking using Bluetooth®)
  
• Apps: CASIO WATCHES
  
• App connectivity feature: Auto time adjustment
  Easy watch setting
  Approximately 300 world time cities
  Flight log
  Phone finder
• Glass: Mineral Glass
  
• Crown: Screw Lock Crown
  
• Surface treatment: Black ion plated bezel
  
• Compatible band size: 145 to 215 mm
  
• Other: Neobrite
• World time: Dual time (Home City time swapping)
  
• Stopwatch: 1-second stopwatch
  Measuring capacity: 23:59'59.
  Measuring modes: Elapsed time, split time
  
• Timer: Countdown timer
  Measuring unit: 1 second
  Countdown range: 24 hours
  Countdown start time setting range: 1 minute to 24 hours (1-minute increments and 1-hour increments)
  
• Alarm/hourly time signal: Daily alarm
  
• Light: LED light (Super Illuminator), Afterglow
  
• Light color: LED:White
  
• Calendar: Full auto-calendar (to year 2099)
  
• Energy saving feature: Power Saving (hands stop to save power when the watch is left in the dark)
  
• Battery display/alert: Battery level indicator
  
• Run time: Approx. battery operating time:
  5 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)
  
• Accuracy: ±15 seconds per month (with no mobile link function)
  
• Date display
  
• Day indicator
  
• Regular timekeeping:
  
• Analog: 3 hands (hour, minute (hand moves every 10 seconds), second), 3 dials (dual time hour and minute, dual time 24-hour, day)