Photo: Tempus Shop
Catalogue / G-Shock / ref. GA-2100-1A1ER
Casio G-Shock GA-2100-1A1ER
The Casio G-Shock GA-2100-1A1ER is a quartz watch, 45.4 mm across, with a mineral crystal, water-resistant to 200 m. It was listed at €99.90 at Tempus at our check on 12 November 2026.
Where to buyChecked 12 November 2026
The button leads to today’s price. Affiliate link: the retailer pays us a commission, at no extra cost to you.
Who it suits
Anyone who swims, dives or wants a watch that never needs babying.
Strengths
Quartz movement · Water-resistant to 200 m · Priced below the brand median
Limits
Mineral crystal · 45.4 mm diameter
Our view
A good choice at this price
Of 11 quartz watches within 20% of its price, none is better equipped (crystal, water resistance, titanium).
Depending on what you want
- If a sapphire crystal matters to you, look at the MTMu Nacré Rose, which has one for €100.
- If your wrist is slim, the MTMu Nacré Blanc measures only 34 mm, at €100.
Reading the spec sheet
What the spec sheet says
- Quartz movement. Accurate and maintenance-free, apart from battery changes.
- Water-resistant to 200 m. Swimming and diving without a second thought.
- Priced below the brand median. It costs 28% less than the median of the 11 quartz G-Shock watches in the catalogue (€139).
- Mineral crystal. It scratches sooner than sapphire, which is usual at this price.
- 45.4 mm diameter. A large case, worth trying on first if your wrist is slim.
Analysis based on the retailer’s spec sheet, without handling the watch.
- Brand
- G-Shock
- Gender
- Men
- Calibre
- 5611
- Strap material
- Resin
- Diameter
- 45.4 mm
- Crystal
- Mineral
- Movement
- Quartz
- Thickness
- 11.8 mm
- Water resistance
- 200 m (20 bar)
- Dial colour
- Black
- Clasp
- Pin buckle
- Weight
- 51g
- Reference
- GA-2100-1A1ER
Questions
The short answers
Is the Casio G-Shock GA-2100-1A1ER an automatic watch?
No. It runs on a quartz movement (calibre 5611).
Can you swim with the Casio G-Shock GA-2100-1A1ER?
Yes. It is water-resistant to 200 m, which covers swimming and diving.
Does the crystal of the Casio G-Shock GA-2100-1A1ER scratch?
It has a mineral crystal, more prone to scratches than sapphire.
What size is the Casio G-Shock GA-2100-1A1ER?
Its case measures 45.4 mm in diameter and 11.8 mm thick.
How much does the Casio G-Shock GA-2100-1A1ER cost?
It was listed at €99.90 at Tempus at our check on 12 November 2026.
Where it ranks
This watch appears in
Same brand
