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Casio’s U.S. GA-2100K collection page lists three G-Shock references: GA2100K-1A, GA2100K-2A and GA2100K-5A. The collection shares a nightlife-inspired design treatment and a set of practical analog-digital features, including 200-meter water resistance and world time for 48 cities.
Which GA-2100K models are listed?
Casio’s U.S. collection page lists these three references:
- GA2100K-1A
- GA2100K-2A
- GA2100K-5A
The collection page establishes the model numbers but does not fully describe each reference’s color treatment in text. Consult Casio’s product imagery to compare the individual versions rather than assuming a specific color from the suffix. Casio’s U.S. GA-2100K collection page is the starting point for the lineup; the official product page for GA2100K-1A provides a model-specific listing.
What makes the design nightlife-inspired?
Casio says the collection takes inspiration from “mysterious, smoky light” and music-driven nightlife. Its design description points to a newly developed dial surface, glossy finish and rich color, with neon accents and translucent, matte-finished bezel and band materials. These are styling details, not a claim that the watches have lighting effects beyond their listed LEDs.
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What features do the three watches share?
Casio’s U.S. collection specifications list the following functions for the GA-2100K lineup:
- Shock-resistant structure
- 200-meter water resistance
- Hand shift function
- World time for 48 cities
- 1/100-second stopwatch
- Countdown timer
- Five daily alarms
- Double LED lighting (Super Illuminator)
Casio Europe’s GA-2100K collection page corroborates the same model references and specifications, describing the water resistance as 20 bar.
Rank #2
- Case
- - Case Material: Resine
- - Case Shape: Round
- - Case Colour: Black
- - Crystal: Mineral crystal
Price, launch timing and availability
Casio’s U.S. product listing for GA2100K-1A showed a price of $135 when indexed in 2026; the listing can change, so check the current official product page for its present price and availability. The reviewed official pages do not establish prices for GA2100K-2A or GA2100K-5A, nor do they confirm a U.S. launch date. Stock and retailer availability may vary.
Quick Recap
Best Value
Rank #4
- Case size (L W H): 48.5 45.4 11.8 mm
- Case and bezel material: Carbon / Resin
- Construction: Shock Resistant Carbon Core Guard structure
- Weight: 51 g
- Water resistance: 200-meter water resistance
Rank #3
- Case size (L W H): 48.5 45.4 11.8 mm
- Case and bezel material: Carbon / Resin
- Construction: Shock Resistant Carbon Core Guard structure
- Weight: 51 g
- Water resistance: 200-meter water resistance
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
