CASIO GA100-1A1 G-Shock watch 55 x 51.2 x 16.9 mm

Big case and chronograph suite

The GA100-1A1 is an analogue-digital sports watch built around a 55 by 51.2 by 16.9 mm stainless-steel case. A 1/1000-second stopwatch with elapsed, lap and split modes plus a speed indicator serves athletes who time short intervals. World time covers 29 zones across 48 cities plus UTC with daylight-saving toggles. Four daily alarms, a snooze alarm and an hourly signal keep schedules on track.

Stainless steel case with rubber strap

The case uses stainless steel and a riveted bezel for structural rigidity while the mineral crystal protects the dial. Large anti-skid pushers give positive actuation even with wet or gloved fingers. A black rubber strap 51 mm wide fastens with a traditional buckle and is not resizable or adjustable. The auto LED light with afterglow illuminates the digital display for low-light reading.

Check wrist fit and feature needs

Verify that the fixed 51 mm band width and non-adjustable length suit your wrist before ordering. Buyers who need a smaller case profile or a metal bracelet should look elsewhere. Confirm that 200-meter water resistance meets your diving requirements. The quartz movement runs on a battery so no winding is required.