New Casio carbon-fiber MTG-B4000 watches with Triple G Resist now available to buy

Alongside the new GBX-H5600 lineup, Casio has also launched two new additions to its premium MT-G line in Japan — the MTG-B4000B-1AJF and MTG-B4000BD-1AJF. Previously announced earlier this year, both are now available to purchase, with a new construction approach that utilizes both carbon fiber and stainless steel with AI-assisted engineering.

Construction and design

The centerpiece of both models is the carbon laminate frame — layers of carbon fiber sheet and fiberglass pressed into complex three-dimensional shapes that practically define the watch's entire profile. You also get a stainless-steel bezel finished with a mix of hairline and mirror polishing, then treated with Black IP coating. The back cover is formed using MIM (Metal Injection Moulding) for precise, protective shaping. The case/bezel material on both variants is carbon fiber reinforced resin, paired with stainless steel.

Casio also adds that the underlying Dual Core Guard structure was developed with the help of AI, making use of accumulated shock resistance data to optimize the design. Both watches carry Triple G Resist certification, covering shock, centrifugal gravity, and vibration resistance.

The two variants can be easily differntiated by their bands. The MTG-B4000B-1AJF uses a resin band with vivid red accents woven through the carbon frame and dial, while the MTG-B4000BD-1AJF steps up to a Layer Composite Band — alternating layers of stainless-steel and carbon fiber reinforced resin — with Black IP treatment on the band as well. The BD variant is heavier for this reason, coming in at 178 g vs 112 g for the B variant.

Both share the same case dimensions of 56.6 × 45.3 × 14.4 mm, anti-reflective-coated sapphire glass, a screw-lock crown, and Neobrite luminous treatment.

Timekeeping and connectivity

Both models feature MultiBand 6 radio wave reception covering Japan, North America, Europe, and China, alongside Bluetooth connectivity for automatic time syncing via the Casio Watches app. App pairing unlocks world time for around 300 cities, automatic time correction, Time & Place logging, watch status display, self-check, and phone finder. Standalone, the watches support 27 cities across 38 time zones plus UTC.

Power

Both run on Tough Solar, rated at approximately 5 months of operation from a full charge without solar generation, or up to 18 months in power-saving mode. Water resistance is rated at 20 BAR.

Pricing and availability

Both models launched on May 15, 2026 in Japan, manufactured domestically. The MTG-B4000B-1AJF is priced at ¥176,000 (~$1,110) while the premium MTG-B4000BD-1AJF with its Layer Composite Band is priced at ¥203,500 (~$1,284).

Alternatively, you can check out the Casio MTG-B1000D-1AJF on Amazon.