Casio G-Shock GA-100 watches

The Casio G-Shock GA-100 is a large analog-digital G-Shock: two hands over a dial set with digital displays, in a 55 mm resin case 16.9 mm thick. The series launched in 2010. It carries on the line that began with the first G-Shock, the DW-5000C of April 1983, which Casio engineer Kikuo Ibe conceived after his father's mechanical watch fell from his wrist and shattered. His goal was "triple 10": a 10-year battery, water resistance to 10 bar and survival of a 10-metre fall.

Inside is module 5081. It runs world time across 48 cities, a stopwatch timed to 1/1000 of a second with a speed indicator, a 24-hour countdown timer, five daily alarms and an LED light with an auto setting. The calendar is fully automatic to 2099. The case is water resistant to 200 metres and magnetic resistant, under a mineral crystal, and a CR1220 cell runs it for about two years. The hands are easy to read, but the LCD displays have no backlight of their own.

The references differ in colour. The GA-100-1A1 is black on black, the GA-100-1A2 adds blue and the GA-100-1A4 red. The A models are the bright ones: the GA-100A-7A "White Ice" and the GA-100A-9A "Bumblebee". The B models come in red (GA-100B-4A) or white and blue (GA-100B-7A). The C models pick out the hands, in green on the GA-100C-1A3 and blue on the GA-100C-8A. The GA-100GD-9A pairs rose gold tones with a champagne dial, the MC models come on a NATO-style strap in grey or orange, and the GA-100MB-1A is black with green.