Casio Casio G-shock GA-2100-1A1ER

Ever since Casio launched the DW-5000C in 1983, G-Shock has been a synonym for durable, shock-resistant timepieces with high functionality. Meanwhile, the Japanese tech giant has sold over 100 million watches under the G-Shock name, making it one of the manufacturer's most successful collections.

The Casio G-Shock ref. GA-2100-1A1ER is part of the Classic collection and is held in high esteem by Casio fans. The watch's design takes inspiration from the first generation DW-5000C models: It keeps the same octagonal shape, but is flatter and lighter, without jeopardizing the watch's robust structure. Another difference from the model's direct ancestor is that Casio gave the GA-2100-1A1ER both an analog and a digital time display.

Casio watches in the GA-2100 series (as well as in the GM-2100 and GA-B2100 series, which came later) were given the nickname CasiOak. This is easily seen in their resemblance to the famous Royal Oak from Audemars Piguet, owing mostly to the octagonal bezel and integrated bracelet. The GM-2100 is the stainless steel version of the GA-2100. The GA-B2100 was the first version to be solar-powered and Bluetooth-compatible.

The 48.5-mm case of the Casio G-Shock GA-2100-1A1ER is made of a combination of synthetic resin and carbon. With a thickness of 11.8 mm and a weight of 51 g, this reference is thinner and lighter than the original from 1983. The heavy-duty material can withstand strong jolts and extreme temperatures.

The G-Shock pulls out all the stops to combine many useful functions in one watch. You can read the time in 31 time zones with the GA-2100-1A1ER, and switch daylight savings on and off. The watch also has a perpetual calendar (up to the year 2099) as well as a stopwatch function, timer, and five daily alarms. The stopwatch function can also display 1/100ths of a second, split times, and 1st and 2nd place times.

The actual time is shown via the analog display (two hands for the hours and minutes), while the LED screen shows the hours, minutes, seconds, 12-hour display, month, and date digitally. The hands and indices are luminous and glow in the dark. The digital display also has a backlight that can be turned on and off.

The unisex watch is equipped with a robust and scratch-resistant mineral crystal and offers water resistance to 200 m (20 bar, 656 ft), making it perfectly suitable for free diving. The battery life is approximately three years. Casio states that the deviation of the quartz movement is +/- 15 seconds per month.

The GA-2100 comes in various color combinations, but Casio only offers the GA-2100-1A1ER in the well-known G-Shock blackout design. In February 2023, the Casio G-Shock GA-2100-1A1ER was selling for around 250 USD on Chrono24. Pre-owned models change hands for around 200 USD. Prices for both new and pre-owned copies had risen dramatically up until June 2022. For example, a new GA-2100-1A1ER, which cost just under 150 USD in December 2020, was demanding close to 370 USD by June 2022. However, prices on the secondary market have been plunging as of late. With that in mind, as of early 2023, it's a good time to buy a G-Shock – the unbreakable retro watch with modern features.