New Casio carbon-steel hybrid MTG-B4000 watches finally available for purchase in the US

Casio’s newest MT-G generation has finally landed on the American G-Shock web store, giving US buyers direct access to the MTGB4000-1A and MTGB4000B-1A2 after weeks of anticipation. While both pieces sport the familiar MT-G tag, almost everything under the hood is fresh.

Casio’s engineers partnered with in-house AI tools to reimagine the Dual Core Guard structure. The result is a hybrid frame that fuses carbon-fiber plates with stainless-steel elements, using a screw-less lug arrangement to keep shock-transfer to a minimum. The 56.6 × 45.3 × 14.4 mm case stays remarkably slim for an MT-G, yet still carries a 200-meter water-resistance rating and G-Shock’s Triple G Resist certification against shock, vibration and centrifugal force.

Tough Solar charging is backed by a five-month autonomy (18 months in power-save mode), and Multi-Band 6 radio reception keeps the analog time display locked to the second. A Bluetooth link to the Casio Watches app adds one-touch world-time selection, phone finder, automatic hand calibration and access to roughly 300 city presets. Riders, runners and travelers will further appreciate the 24-hour stopwatch and countdown timer, while a bright white Super Illuminator LED should take care of low light readability.

There are two US launch variants

• MTGB4000-1A – $1,250: Stainless-steel bezel, raw carbon accents, black resin strap.
• MTGB4000B-1A2 – $1,350: Dark ion-plated bezel, midnight-blue carbon frame, matching hardware.

Both models weigh in at 112 g - somewhat light by MT-G standards - thanks to the carbon composite mid-case and the elimination of metal screws at the lugs. Domed sapphire crystal with inner AR coating, knurled screw-lock crown and Neobrite-filled indices round out the premium build.

As of today, the MTGB4000 duo is listed as "Buy Now" on the official G-Shock US site, with free domestic shipping and a standard one-year warranty (extendable to three years via Casio’s registration program). Given the brisk sell-outs that we've seen with earlier MT-G drops, interested buyers may want to move quickly - especially those eyeing the stealthier B-1A2 colorway, which bundles the full feature set in one of Casio’s darkest MT-G finishes to date.

For those who felt the MTG-B3000 (Casio MTG-B3000PRB-1AJR curr. $1,200 on Amazon) was a leap forward but still craved a more aggressive look, the MTGB4000 should hit the sweet spot, with carbon tech, AI-guided design and old-school G-Shock traits in a package finally available without an overseas import premium. However, users over on aBlogtoWatch weren't too happy with the design and the usage of AI while designing the timepiece, so that might be something worth looking into.