Designed with a slimmer and more compact design this G-SHOCK model GMAS120RB-1A is the midsize version of the iconic analog-digital GMAS120. The black and deep red colour scheme, with a glossy metallic finish gives the watch a touch of sophistication.

- 49 × 45.9 × 15.8mm Case Size
- Resin Case and Bezel
- Resin band
- Mineral Glass
- Shock Resistant
- Magnetic Resistant
- 200 Meters Water Resistant
- LED light Auto light switch, selectable illumination duration (1.5 seconds or 3 seconds), afterglow
- LED: Amber
- World time: 29 time zones (48 cities + coordinated universal time), daylight saving on/off, home city/world time city swapping)
- Stopwatch
- Countdown Timer
- Alarm: 5 daily alarms (with 1 snooze alarm)
- Mute feature: Button operation tone on/off
- Calendar: Full auto-calendar (to year 2099)
- Accuracy: ±15 seconds per month
- 12/24-hour format
- Regular timekeeping: Analog: 2 hands (hour, minute (hand moves every 20 seconds)), 1 dial (speed). Digital: Hour, minute, second, pm, month, date, day
- Hand shift feature (Hands move out of the way to provide an unobstructed view of digital display contents.)
- Approx. battery life: 3 years on CR1220