G-Shock GA-100-1A4 Black Resin Analog-Digital Watch

The G-Shock GA-100-1A4 is a black resin analog-digital watch made for men who want a tough timepiece for daily wear and active use. It pairs analog hands with a digital display, and its shock-resistant, magnetic-resistant build with 200-meter water resistance is the main reason to choose it.

The G-Shock GA-100-1A4 analog-digital watch covers travel and training with world time across 29 time zones, a 1/1000-second stopwatch and a 24-hour countdown timer that can repeat automatically. Five daily alarms, one with snooze, and an hourly time signal help you keep to a schedule. An LED amber light with afterglow makes the display readable in low light, while the full auto-calendar runs to 2099 and timekeeping stays within ±15 seconds per month. The CR1220 battery is expected to last about two years.

Key features and benefits of the G-Shock GA-100-1A4

• Shock and magnetic resistance: The resin case and bezel are built to absorb knocks, and the magnetic-resistant construction limits interference from nearby magnets. That helps the watch keep accurate time during rough daily use.
• 200-meter water resistance: The watch is rated for water pressure at 200 meters, which covers swimming and snorkeling. It is not a cue to press the buttons while underwater.
• World time across 29 time zones: You can read the time in 48 cities plus UTC, with daylight saving adjustments and city swapping. This is useful when you travel or work with people in another country.
• 1/1000-second stopwatch: The stopwatch records elapsed, lap and split times up to 99:59'59.999'', and it accepts speed and distance input. Athletes and coaches can use those readings to compare efforts.
• 24-hour countdown timer: The timer works in 1-minute and 1-hour increments with auto-repeat. Interval sessions and reminders can run without resetting the timer after each cycle.
• Five daily alarms: Five alarms, one snooze function and an hourly time signal are included. They give you several prompts across the day without needing a phone.
• LED amber light: The light has an auto switch, a selectable 1.5 or 3-second duration and afterglow. Reading the display in a dark room or at night is easier.
• Full auto-calendar and accuracy: The calendar is programmed to the year 2099, and accuracy is listed at ±15 seconds per month. You can leave the date alone and still get a steady time reference.
• 12/24-hour format and regular timekeeping: You can choose a 12-hour or 24-hour display. The analog side uses two hands for hour and minute plus a speed dial, while the digital side shows hour, minute, second, pm, month, date and day.
• Case size and weight: The case measures 55 × 51.2 × 16.9 mm and the watch weighs 70 g. The broad face gives a clear read, and the low weight suits all-day wear.
• Resin case and band: Resin is used for the case, bezel and band. The material keeps the watch light and is easy to rinse after active use.
• CR1220 battery: The watch runs on a CR1220 battery with an approximate 2-year life. That keeps battery changes infrequent compared with a shorter cycle.

Who the analog-digital watch is for

The G-Shock GA-100-1A4 suits men who want one watch for work, travel and active days. Its resin build, 200-meter water resistance and 70 g weight make it easy to wear for long periods, while world time, alarms and the stopwatch cover schedules and training. It is a practical choice if you like analog hands but also want digital readouts and timing tools.

• Travelers who need time in 48 cities plus UTC and want daylight saving adjustments in the watch.
• Athletes timing laps, splits or intervals with a 1/1000-second stopwatch and 24-hour timer.
• Swimmers and snorkelers who need a 200-meter water resistance rating for water sessions.
• People with a busy schedule who use five daily alarms, a snooze function and an hourly time signal.
• Outdoor users who want a shock-resistant, magnetic-resistant watch in a resin case and band.

Less suitable if: you want a fully analog watch and do not want digital displays, alarms or timing functions.

Analog-Digital Watch specifications

Using and caring for the G-Shock GA-100-1A4

The resin case and band take everyday knocks, and the 200-meter rating allows swimming and snorkeling. Rinse the watch in fresh water after saltwater or chlorine, and keep the buttons untouched while you are underwater. The CR1220 battery has an approximate 2-year life, so arrange a replacement when the display or light becomes weak.

• Rinse with fresh water after saltwater or chlorine to keep the resin case and band clean.
• Do not press the buttons underwater, so the 200-meter water resistance stays intact.
• Replace the CR1220 battery when timekeeping slows or the LED light dims, based on the approximate 2-year life.
• Store the watch in a dry place to limit moisture exposure when it is not in use.

How to choose the right analog-digital watch

When you choose an analog-digital watch, start with the conditions you will wear it in. For toughness, the G-Shock GA-100-1A4 lists shock resistance and magnetic resistance, plus 200-meter water resistance for swimming and snorkeling. For travel, it covers 29 time zones across 48 cities and UTC; for training, it adds a 1/1000-second stopwatch and a 24-hour timer. Comfort comes from the resin case and band and a 70 g weight, while the 55 × 51.2 × 16.9 mm case gives a substantial wrist presence.

Frequently asked questions

What is the G-Shock GA-100-1A4?

The G-Shock GA-100-1A4 is a black resin analog-digital watch with shock-resistant and magnetic-resistant construction. It also has 200-meter water resistance, world time and a set of digital timing tools.

What materials does the G-Shock GA-100-1A4 use?

The case, bezel and band are made of resin. That material keeps the watch at 70 g and supports the black finish shown in the model name.

Can I swim or snorkel with the G-Shock GA-100-1A4?

Yes. The watch has a 200-meter water resistance rating, which covers swimming and snorkeling. Keep the buttons untouched while underwater to protect that rating.

How does world time work on this analog-digital watch?

World time covers 29 time zones in 48 cities plus UTC. You can use daylight saving adjustments and city swapping to read another location without changing the main time.

How long does the CR1220 battery last?

The CR1220 battery has an approximate 2-year life. Replace it when the display slows or the LED amber light becomes dim.

What timing features does the G-Shock GA-100-1A4 include?

It includes a 1/1000-second stopwatch that reads up to 99:59'59.999'' with speed and distance input, plus a 24-hour countdown timer with auto-repeat. Five daily alarms, one snooze function and an hourly time signal cover daily schedules.

How should I care for the resin band?

Rinse the resin band with fresh water after saltwater or chlorine, and store the watch in a dry place. Avoid pressing buttons underwater so the 200-meter water resistance is not compromised.