Casio is releasing a new analog-digital G-Shock G-STEEL series that has the same look and features as the GST-S100 and GST-W100 series but in a smaller mid-size form factor that is about 90% the size of the original G-STEEL. The G-STEEL GST-W300, GST-W310, and GST-S310 have a smaller size of 55.9 x 49.3 x 15.3 mm compared to the original G-STEEL size of 59.1 x 52.4 x 16.1. These models will appeal to those with small wrists or those who prefer a more formal-looking analog G-Shock that isn’t the usual extra-large size. The GST-W300 and GST-W310 models with Tough Solar and Multi-Band 6 automatic time adjustment are likely to be released in Japan and Asia only, but Casio has also announced the Tough Solar-equipped silver GSTS310D-1A with stainless steel band for a U.S. release.
Update: The GST-W300-1AJF, GST-W300BD-1AJF, GST-W300G-1A2JF, GST-W300G-1A9JF, and GST-W310D-1AJF are June 2017 releases in Japan.
Update 2: The GST-S300-1A, GST-S300BD-1A, GST-S300G-1A2, GST-S300G-1A9, GST-S310D-1A are June 2017 releases for the rest of Asia. These watches have Tough Solar power but not Multi-Bannd 6 timekeeping like the Japanese versions. This raises the possibility that more of these mid-size G-STEEL watches may be released in America in addition to the GSTS310D-1A.
Update 3: Along with the stainless steel-banded GSTS310D-1A (list price $350 USD), Casio America is also releasing the blue GSTS300G-1A2 and gold GSTS300G-1A9 with a list price of $280 USD each. These three models are scheduled for a July 2017 release in the U.S.
The G-STEEL line is known for its classy analog-digital design, stainless steel body, and a dual-layer bezel for extra protection. With its mature look, shock resistance, and 200-meter water resistance, The G-Shock G-STEEL line is suitable for both outdoor activities and more formal environments like the office and social functions. With the Tough Solar power system that uses a rechargeable battery, the G-STEEL GST-S310 and GST-W300 are maintenance-free watches that can be worn for all occasions. Other features include neo-brite luminous hands, world time (48 cities + UTC), 1/100 second stopwatch, countdown timer, 5 daily alarms, battery level indicator, and full auto double LED light with afterglow.
GST-S310D-1A: (Silver) Tough Solar, silver body, silver stainless steel band, stainless steel outer bezel. List price $350 USD.
GST-S300G-1A2: (Blue and Black) Tough Solar, blue IP body, black resin band, resin outer bezel. List price $280 USD.
GST-S300G-1A9: (Gold and Black) Tough Solar, gold IP body, black resin band, resin outer bezel. List price $280 USD.
GST-S300-1A: (Silver and Black) Tough Solar, silver body, black resin band, resin outer bezel.
GST-S300BD-1A: Tough Solar, black IP body, black IP stainless steel band, resin outer bezel.
The following models are for the Japanese domestic market. The difference from the previous models is that these models have Multi-Band 6 atomic time syncing.
GST-W300-1AJF: (Silver and Black) Tough Solar/Multi-Band 6, Silver body, black resin band, resin outer bezel. List price is ¥35,000 JPY.
GST-W300BD-1AJF: (Black) Tough Solar/Multi-Band 6, Black IP body, black IP stainless steel band, resin outer bezel. List price is ¥52,000 JPY.
GST-W300G-1A2JF: (Blue and Black) Tough Solar/Multi-Band 6, Blue IP body, black resin band, resin outer bezel. List price is ¥40,000 JPY.
GST-W300G-1A9JF: (Gold and Black) Tough Solar/Multi-Band 6, Gold IP body, black resin band, resin outer bezel. List price is ¥40,000 JPY.
GST-W310D-1AJF: (Silver) Tough Solar/Multi-Band 6, Silver body, silver stainless steel band, stainless steel outer bezel. List price is ¥45,000 JPY.
Update: More mid-size model options have been added. Visit: New Colors For Mid-Size G-STEEL 300: Black, Red, Silver, White





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Love how 55.9 mm is considered ‘small’ 🙂
Changed it to “smaller” just for you
Any ballpark estimate as to when these will be available for purchase? I haven’t followed Casio’s Basel releases in the past so I can’t estimate a time frame. Thanks
G-Shock Japan just listed these for a June 2017 release. Should be seeing the GSTS310D-1A in the U.S. by July or August.
Do you know the price for US launch? and does it has all features like Japan/Asia?
All we know is that the GSTS310D-1A (with stainless steel band) will be getting a US release sometime. Don’t know the price yet. It has Tough Solar power (designated by the “S” in the model number) but not Multi-Band 6 timekeeping like the Japanese models (designated by the “W”).
Weird question, but can you confirm that the bracelets on these new models are interchangeable with the older, larger series G-Steels? For example could I slap a GSTS110D steel bracelet on a GST-W310?
Not certain but I would assume the bands are a different size.
Congrats Casio engineering team!!! A “G-Stell” series litlle bit smaller (just a little… in my poor opinion could be a litlle bit more smaller…).
But i miss one option of color, the full black (as like: GST-S100G-1B)! I Hope that Casio launch the full black smaller mid size! You think that this it is possible @G-Central??? Or i’m a dreamer about this possibility?
My sincere lengths for the great website!
From Brazil, Guilherme.
Yeah an all-black model would be great. I think is very possible we will see more mid-size models.
Thanks by your fedd-back!
Awesome, lets crossing fingers and wait!
There’s an all black model coming! https://www.g-central.com/new-colors-mid-size-g-steel-300-black-red-silver-white/
OHHH!!!! Great!!!!
thanks, only now i saw your post! that GST-S300G-1A1 is what i was looking for! it was worth waiting for…
So I have a question, is the GST-S100 is the same size as G-STEEL GST-W300, GST-W310, and GST-S310?
Not the same size, the 100-series is bigger than the 300-series.
100-series (S/W1XX models): 59.1 x 52.4 x 16.1mm
300-series (S/W3XX models): 55.9 × 49.3 × 15.3 mm
Hello there, I just bought the all black GST-S100G-1BCR and pretty happy with its size. My question is among the all black one I have, the black-silver one GST-S110-1A and the other black-silver one GST-W300-1AJF, are they different in size? If so, which one is the smallest?
The GST-W300-1AJF is smaller than the other two.
100-series (S/W1XX models): 59.1 x 52.4 x 16.1mm
300-series (S/W3XX models): 55.9 × 49.3 × 15.3 mm
I have one more question, I search the GST-S300-1A and GST-W300-1A they look very similar to each other, if not identical. What is the difference between them?