Casio G-Shock GA-2100-1A1 'CasiOak'
G-Shock · Casio

Casio G-Shock GA-2100-1A1 'CasiOak'

Ref. GA-2100-1A1 · Amazon ASIN B07WGJ1JNW
Digital quartz (analog-digital)Mineral crystal200 m45.4 × 48.5 mm

The octagonal analog-digital G-Shock in all black: carbon core guard case, 200 m water resistance, 11.8 mm thick, mineral crystal. World time, stopwatch and LED light.

Case diameter45.4 mm
Lug-to-lug48.5 mm
Thickness11.8 mm
Warranty1 years
Fits wrist from17.5 cm (6.9″)
Amazon price · new
$107.95
Value Score
73 of 100
Spec points
49
vs. type median
+16% ($93)
Amazon sales rank
#403 wrist watches
View GA-2100-1A1 on Amazon

Not in stock today (ships later) · sold by Direct Time. Price as of November 3, 2026, 18:15 UTC.

Wrist fit

Will the Casio G-Shock GA-2100-1A1 'CasiOak' fit your wrist?

Enter your wrist circumference. The drawing scales the case (45.4 mm across, 48.5 mm lug-to-lug) against the flat top of a wrist that size, using the 3.6× lug-to-lug rule from our fit guide. Needs JavaScript; the rule itself is on the fit guide.

Specifications

What you get

Published manufacturer specifications. Fields we could not verify are left out rather than guessed.

ReferenceGA-2100-1A1
MovementDigital quartz (analog-digital)
CrystalMineral
Water resistance200 m
Case diameter45.4 mm
Lug-to-lug48.5 mm
Thickness11.8 mm
Strap / braceletResin
LumeYes
Calendardate, day
Warranty1 years
Fits wrist from17.5 cm (6.9″)
Value Score

How the 49 spec points add up

Value Score = 100 × √(spec points per dollar ÷ the best ratio among G-Shock watches in stock on Amazon today). Full methodology.

Digital quartz+14
Mineral crystal+8
200 m water resistance+17
Resin strap+3
Luminous hands and markers+4
Date+2
Day+1
Spec points49
Head to head

Comparisons with the Casio G-Shock GA-2100-1A1 'CasiOak'

FAQ

Questions about the Casio G-Shock GA-2100-1A1 'CasiOak'

How much does the Casio G-Shock GA-2100-1A1 'CasiOak' cost on Amazon?
As of November 3, 2026, 18:15 UTC, the Casio G-Shock GA-2100-1A1 'CasiOak' (GA-2100-1A1) is listed new on Amazon at $107.95, sold by Direct Time. That is 16% above the median of the 8 G-Shock watches we track with a live price ($93). Prices change; the price shown on Amazon at checkout applies.
What is the Value Score of the Casio G-Shock GA-2100-1A1 'CasiOak'?
Value Score 73. It earns 49 spec points (Digital quartz (analog-digital), mineral crystal, 200 m water resistance) and today's price of $107.95 gives 45.4 points per $100. The score is 100 times the square root of that ratio divided by the best ratio among G-Shock watches in stock on Amazon today. The formula is published on our methodology page.
What wrist size fits the Casio G-Shock GA-2100-1A1 'CasiOak'?
The case is 45.4 mm across. We do not have a verified lug-to-lug figure for this reference, so we do not publish a wrist-fit estimate.
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Guides that apply to this watch