Casio has expanded its premium MT-G watch family in Japan with the launch of the new MTG-B4000 series, bringing together carbon fiber construction, stainless steel detailing, solar power, Bluetooth connectivity, and high-end shock resistance. The two new models, the MTG-B4000B-1AJF and MTG-B4000BD-1AJF, are now available in Japan, aimed at buyers who want a rugged G-Shock with a more refined, luxury-focused design.
The highlight of the Casio MTG-B4000 lineup is its advanced carbon laminate frame. Casio uses layers of carbon fiber sheet and fiberglass, pressed into a complex three-dimensional structure that shapes much of the watch’s profile. This gives the watches a strong yet lightweight foundation while adding a distinctive premium look that fits the MT-G series.
Both models also feature a stainless steel bezel with a combination of hairline and mirror-polished finishing. A Black IP coating adds a dark, stealthy appearance while improving durability. The rear cover is made using Metal Injection Moulding, a process designed to create precise, protective components for the case structure. The case and bezel combine carbon fiber reinforced resin with stainless steel, giving the watches a balance of toughness and upscale styling.
Casio says the internal Dual Core Guard structure was developed using AI-assisted engineering based on shock-resistance data. The result is a design built to withstand demanding conditions. Both MTG-B4000 models come with Triple G Resist protection, meaning they are engineered to resist shock, centrifugal force, and vibration.
Although the two watches share the same core design, the biggest difference is the band. The MTG-B4000B-1AJF comes with a resin band and red accents woven through the carbon frame and dial, giving it a sportier and more aggressive look. The MTG-B4000BD-1AJF is the more premium version, featuring a Layer Composite Band made from alternating layers of stainless steel and carbon fiber reinforced resin. This version also receives Black IP treatment on the band for a more unified dark finish.
Because of the different band materials, the two models vary noticeably in weight. The MTG-B4000B-1AJF weighs 112 grams, while the MTG-B4000BD-1AJF comes in at 178 grams. Both watches measure 56.6 × 45.3 × 14.4 mm, making them substantial but still wearable for a feature-packed premium G-Shock.
For durability and daily usability, both versions include sapphire crystal with anti-reflective coating, a screw-lock crown, and Neobrite luminous treatment for improved visibility in low light. Water resistance is rated at 20 BAR, making the watches suitable for swimming and other water-based activities.
Timekeeping is another major strength of the Casio MTG-B4000 series. Both models support MultiBand 6 radio-controlled time adjustment in Japan, North America, Europe, and China. They also include Bluetooth connectivity, allowing the watches to sync automatically through the Casio Watches app.
When paired with the app, users gain access to world time for around 300 cities, automatic time correction, Time & Place logging, watch status display, self-check functions, and phone finder support. Without the app, the watches still offer world time for 27 cities across 38 time zones, along with UTC.
Power comes from Casio’s Tough Solar system. On a full charge, the watches can run for around five months without additional solar charging. With power-saving mode enabled, battery life can extend up to approximately 18 months. This makes the MTG-B4000 series a low-maintenance option for users who want premium features without frequent charging.
The Casio MTG-B4000B-1AJF and MTG-B4000BD-1AJF launched in Japan on May 15, 2026, and are manufactured domestically. The MTG-B4000B-1AJF is priced at ¥176,000, which is around $1,110. The higher-end MTG-B4000BD-1AJF, equipped with the Layer Composite Band, is priced at ¥203,500, or roughly $1,284.
With its carbon fiber construction, Triple G Resist protection, Tough Solar power, Bluetooth syncing, sapphire glass, and premium finishing, the Casio MTG-B4000 series is positioned as a strong choice for collectors and everyday users looking for a high-performance luxury G-Shock.
