Name: Casio G-Shock Classic Watch GA-B2100-1A1ER
Brand: Casio
SKU: GA-B2100-1A1ER
Price: 154.44 USD
Availability: OutOfStock
Rating: 5 (8 reviews)

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The Casio G-Shock GA-B2100-1A1ER, the GA-2100 with Bluetooth connectivity in total black finish. Analog-digital watch with module 5689, Carbon Core Guard structure and smartphone connection. At 52 grams and 11.9mm thick, it combines the iconic octagonal design with smart technology. Matte black resin case, stealth dial with analog subdial and integrated digital display.

More details

Case Made of	Resin
Case Size (Diameter)	46 mm
Case Color	Black
Case Thickness	11.9 mm
Case Shape	Octagonal
Glass made of	Mineral
Face Color	Black
Bezel material	Plastic / Resin
Strap made of	Resin
Strap Color	Black
Strap length	145 - 215 mm

Water Resistance	20 ATM
Type of Movement	Solar
Type of Display	Anadigi
Made for	Men
Connectivity	Bluetooth® Smart
Collection	G-SHOCK
Alarms	Sound Alarm(s) - 5 Daily Alarms
Battery level indicator	Yes
Illuminator	Super Illuminator
Automatic calendar	Yes
Button tone activated/deactivated	Yes
Resistance	Shockproof
Solar energy system	Yes
Chronometer	1/100 s - 24 h
Dimensions (H x W x D)	48,5 mm x 45,4 mm x 11,9 mm
Time Zone	Yes
Battery	CTL920
Movement Brand	Casio
Caliber	5689
Brand	Casio
Weight (g)	52
Color	Black

Description

Introducing the Casio G-Shock GA-B2100-1A1ER, the connected evolution of the legendary GA-2100 in its most technological interpretation. This total black version displays impeccable stealth aesthetics: octagonal matte black resin case, black dial with indices barely perceptible under direct light, and a monochromatic finish only broken by luminescent grey hands and the compact digital display. The analog subdial at 9 o'clock and digital window at 3 create perfect visual balance in the minimalist architecture characteristic of the GA-2100.

At its heart beats the Casio 5689 module, an analog-digital caliber with Bluetooth connectivity that transforms this G-Shock into a discreet smartwatch. The main hands mark hours, minutes and seconds, while the analog subdial can display a second time zone. The digital display integrates multiple functions: 1/100 second stopwatch up to 24 hours, countdown timer, 5 independent alarms, automatic calendar to 2099, and world time with 38 time zones. Bluetooth connectivity enables automatic time synchronization via smartphone, function configuration through the G-Shock Connected app, and basic notifications.

G-Shock was born in 1983 from engineer Kikuo Ibe's dream of creating an indestructible watch. After more than 200 prototypes and drop tests from 10 meters high, a legend was born that has defined sports watchmaking for four decades. The GA-2100, launched in 2019, revolutionized the collection by combining G-Shock resistance with an ultra-thin octagonal design of 11.8 mm and 51 grams, becoming a cult icon almost overnight.

Shopping at TicTacArea.com means buying from real jewelers with over 30 years of industry experience, serving as official distributors, online since 1999. Every product is genuine, factory-new, and delivered with its official presentation box, documentation, and international warranty.

Technical Specifications

Reference: GA-B2100-1A1ER
Module/Caliber: 5689
Type: Analog-digital
Movement: Tough Solar quartz
Water resistance: 200 meters
Shock resistance: Carbon Core Guard structure
Case material: Resin
Case color: Matte black
Strap material: Resin
Strap color: Black
Dial color: Stealth black
Crystal: Mineral
Light: White LED
Diameter: 45.5 mm
Thickness: 11.9 mm
Weight: 52.0 g
Functions: Bluetooth, Tough Solar, stopwatch, timer, 5 alarms, world time, auto calendar
Battery: CTL920
Made for: Men

User manual

Download the manual in English (PDF)

By Ashton H. on 15 Oct. 2026 :

Title : Casio GShock 2100 b tough solar
Comment : Great handsome watch lightweight and tough especially for the price and came earlier than expected. Tictacarea is the best place in my opinion to buy Casios and Gshocks online they are much cheaper and the shipping is free and good. The watch I got is originally 165 usd not accounting for shipping or tax and I got this for 118 usd total.

By John W. on 22 Sept. 2026 :

Title : Perfect
Comment : Great watch. Stealthy looks with nice features. The solar charging and Bluetooth make set up and the complications simple. There’s no wrist tilt light on this model but that’s no biggy. I love Casio and what they do. I’m guessing this will be a watch for life. Tic tac have been awesome by the way. I received this watch on day six from Spain to Wales. Very competitive pricing and free postage. Highly recommended Tic tac. Thanks

By Krzysztof S. on 08 May 2024 :

Title : Mr Krzysztof Sierocinski
Comment : The item is just awesome and tic tac area is the best gshock shop Ive ever seen

By Dave C. on 19 March 2024 :

Title : Very pleased with this watch
Comment : Bought from Canada. Took about 2-3 weeks for standard shipping. Very happy with the quality of this G Shock so far. I have a 7.25 inch wrist and I was worried the watch might look to big on me. But I'm glad to say that it looks smaller in person compared to the close up shots online.

By Raymond C. on 17 March 2023 :

Title : Clean design
Comment : Nice watch, but one thing I don't like is the smaller hand isn't indicating week of the day like the non-bluetooth version.

By Michael Z. on 14 March 2023 :

Title : Amazing little G-Shock
Comment : I have owned G-Shocks for a while now, and they are my favorite travel/beater watches. I currently have a GX-56BB-1, and it has been with me on many adventures in quite a few countries. My biggest gripe with it was that it was a bit too big to wear every day, especially with the log sleeves. I wanted to get the original Casioak, but lack of Tough Solar was a deal breaker for me.Well, this murdered out version with Buletooth and solar charging is a winner. I cannot get this specific model (all black) in Canada, so I ordered it here.Amazing price (almost $100 cheaper than local), fast shipping, genuine product - five stars all around. Keep up the good work, TicTacArea team!