Introduction
This manual provides detailed instructions for the proper use and care of your CASIO G-SHOCK G-Steel Tough Solar Multi-Band 6 watch, model GST-W310-1AJF. This timepiece combines the renowned G-SHOCK durability with advanced features such as Tough Solar power and Multi-Band 6 atomic timekeeping, ensuring reliable performance and accurate timekeeping.

Image: The G-SHOCK G-Steel GST-W310-1AJF watch displayed on a wrist, showcasing its design and size.
Setup
Initial Charging (Tough Solar)
Your G-SHOCK watch is equipped with Tough Solar technology, which converts light into electrical power. Before initial use, or if the watch has been stored in darkness, expose the watch face to bright light for several hours to ensure a full charge. The watch contains a secondary battery that stores this energy.
- Place the watch where its face is exposed to direct sunlight or strong artificial light.
- Avoid placing the watch in extremely hot environments during charging.
- A fully charged watch can operate for approximately 7 months without further light exposure under normal use, or up to 18 months in power-saving mode.

Image: Illustration of the watch's solar charging capability and its ability to receive time calibration signals from a radio tower for accurate timekeeping.
Time Zone and Automatic Time Adjustment (Multi-Band 6)
The Multi-Band 6 feature allows your watch to automatically receive time calibration signals from six transmission stations around the world, ensuring highly accurate timekeeping. You will need to set your home city (time zone) first.
- Enter Timekeeping Mode: Ensure the watch is in the regular timekeeping mode.
- Access Home City Setting: Press and hold the 'Adjust' button (usually top-left) until the city code starts to flash.
- Select Home City: Use the 'Forward' (usually top-right) and 'Reverse' (usually bottom-right) buttons to scroll through the city codes and select your desired home city.
- Confirm Setting: Press the 'Adjust' button again to exit the setting mode.
Once your home city is set, the watch will attempt to receive time calibration signals automatically overnight. For manual reception, refer to the 'Operating' section.
Operating Instructions
Basic Timekeeping Mode
In the basic timekeeping mode, the watch displays the current time, day of the week, and date. The digital display provides additional information.
- Mode Button: Press the 'Mode' button (usually bottom-left) to cycle through different modes: Timekeeping, World Time, Stopwatch, Timer, Alarm.
- Light Button: Press the 'Light' button (usually top-right) to illuminate the display with the Double LED light.
Hand Shift Feature
The watch features a hand shift function (針退避機能) that temporarily moves the analog hands away from the digital display, allowing for easier viewing of digital information. To activate this feature, typically press a combination of buttons (refer to the full manual for specific button combinations, usually 'Mode' and 'Light' simultaneously or a long press of 'Mode').
Shock and Water Resistance
The GST-W310-1AJF is designed with G-SHOCK's signature shock-resistant structure, protecting it from impacts and vibrations. It also boasts 200-meter (20 ATM) water resistance, making it suitable for daily use, unexpected bad weather, swimming, and skin diving. It is not suitable for scuba diving requiring helium gas.

Image: A G-SHOCK watch submerged in water and another showing dynamic movement, illustrating its robust shock and 200-meter water resistance.
Maintenance
Solar Charging Guidelines
To maintain optimal performance, ensure your watch receives regular light exposure. If the charge level drops, the watch may enter power-saving mode or some functions may become unavailable. A low battery indicator will appear on the digital display.
- Daily Exposure: Try to expose the watch to light daily, even if for a short period.
- Long-Term Storage: If storing the watch for extended periods, ensure it is in a location where it can receive light.
- Avoid Overheating: Do not place the watch on the dashboard of a car or near other heat sources during charging, as high temperatures can damage the watch.
Cleaning Your Watch
Regular cleaning helps maintain the appearance and longevity of your watch.
- Wipe the watch case and band with a soft, dry cloth.
- For dirt or grime, use a soft cloth dampened with water and a mild neutral detergent, then wipe dry.
- After exposure to saltwater, rinse the watch thoroughly with fresh water and wipe it dry.
- Do not use volatile agents like thinner, gasoline, or alcohol, as they may damage the watch's resin components.
Troubleshooting
Time Synchronization Issues
- No Signal Reception: Ensure the watch is placed in a location where it can receive radio signals, typically near a window, away from metal objects or electronic devices that may cause interference.
- Incorrect Home City: Verify that your home city setting is correct for your current time zone.
- Manual Reception: If automatic reception fails, attempt a manual reception. Refer to the full manual for specific steps to initiate manual time calibration signal reception.
Power Issues (Low Charge)
- Watch Stops or Functions Malfunction: This indicates a low battery charge. Expose the watch to bright light for an extended period (several hours to a full day) to fully recharge it.
- Power Saving Mode: If the watch is left in darkness, it may enter power-saving mode, where the display turns blank to conserve power. Exposing it to light will reactivate the display.
Specifications
| Model Number | GST-W310-1AJF |
| Brand | G-Shock |
| Manufacturer | CASIO |
| Movement Type | Japanese Quartz |
| Power Source | Tough Solar (Solar Powered) |
| Timekeeping | Multi-Band 6 Atomic Timekeeping |
| Display | Analog-Digital |
| Water Resistance | 200 Meters (20 ATM) |
| Shock Resistance | Yes (G-SHOCK Structure) |
| Case Material | Plastic |
| Band Material | Plastic |
| Case Diameter | 49.3 Millimeters |
| Case Thickness | 15.3 Millimeters |
| Item Weight | 92 Grams |
| Battery | 1 CR2 (included, secondary for solar) |
| First Available | September 1, 2017 |

Image: A visual comparison between the GST-W110-1AJF and GST-W310-1AJF models, highlighting their respective dimensions (55.9 x 49.3 x 15.3 mm for GST-W310-1AJF) and weights (92g for GST-W310-1AJF).
Warranty Information
CASIO watches typically come with a manufacturer's warranty covering defects in materials and workmanship. The specific terms and duration of the warranty may vary by region and retailer. Please retain your proof of purchase.
For detailed warranty information, including coverage, exclusions, and how to make a claim, please refer to the official CASIO website or the warranty card included with your purchase.
Customer Support
Should you require further assistance, have questions about your watch's operation, or need repair services, please contact CASIO customer support.
- Official CASIO Website: Visit the official CASIO website for your region to find FAQs, detailed manuals, and contact information for customer service.
- Service Centers: Information on authorized service centers can also be found on the CASIO website.
When contacting support, please have your watch model number (GST-W310-1AJF) and purchase details readily available.