Whatever you’re doing, wherever you are — the G-SHOCK Master of G line has your back. Based on GRAVITYMASTER, MUDMASTER, and MUDMAN models that deliver peak performance in punishing conditions in the air and on land, this line features a black watch case symbolizing toughness, with accents in vivid emergency colors that capture the world of professionals involved in rescue efforts and other critical missions. The organic form of the GRAVITYMASTER GR-B300EC 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.
Case size (L× W× H): 59 × 54.7 × 15.7 mm
Weight: 71 g
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)
Other features: 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)
Watches.com will cover the cost for Standard International Mail* (orders over $249+) and Standard Domestic Mail (orders over $100+). Not all countries are eligible for free international shipping. Upgraded shipping options (estimated transit times and rates) will be quoted during checkout.
Watches.com has been shipping worldwide since 1999 and we ship internationally daily. Most orders are processed and shipped out by 5pm (MST) Monday through Friday on regular business days. Payment/fraud verification is typically instantaneous, but in some instances may take up to 48 hours. Orders placed/received after 12:00pm (MST) will be processed the next business day. Please be aware that UPS does not deliver on weekends.
Because customs fees vary by country, we do not collect duties during checkout. If duties are due, your customs agency will let you know when the package arrives in your country. It is your responsibility to pay these fees to your country.
Once items are shipped, liability is covered by the terms of the carrier. We will ship to the address specified by the customer. If you did not provide us with an accurate address, neither Watches.com, nor the shipping carrier can be held responsible for the loss of an item. Please double check your shipping address. Any shipping damage must be reported to Watches.com within 48 hours of delivery, otherwise it is ineligible for any insurance or refund claims.
Note: Per Casio's policy, Casio and G-Shock watches are not eligible for International Shipping. Any international order containing a Casio or G-Shock watch will be cancelled and all monies refunded.
We could all use some extra time. If your new, unworn item is not 100% to your satisfaction, you have 30 days from the original ship date to return it. To be eligible for a return, your item must be unused, unworn and in the same condition that you received it (including any protective stickers still on it). It must also be in the original packaging. More details can be found on our Returns page. **Unfortunately Mystery watches are final sale and only eligible for return for store credit; a small restocking fee applies to these returns.
