Casio appears to be readying a premium addition to its fitness-focused ‘G-Squad’ lineup, a move that would signal its first true smartwatch launch in over two years.
According to a leak from the Japanese blog Great G-Shock World, a new model (designated GM-H5600) has appeared in multiple Asian certification databases, suggesting a launch is imminent in the first half of 2026.
The rumored GM-H5600 looks set to merge two of Casio’s most successful modern concepts: the advanced health-tracking sensors of the DW-H5600 and the high-end metal construction of the ‘Full Metal’ GM-5600 series.
If the leaks are accurate, this would be the first classic square-faced G-Shock to feature an optical heart rate sensor while ditching the resin case for a more lifestyle-oriented metal bezel.


Health tracking meets rugged metal
It’s expected that the internal hardware will closely mirror the existing DW-H5600 released in 2023 (and shown above). This would mean a suite of Polar-powered health algorithms, covering:
- Continuous heart rate and blood oxygen (SpO2) monitoring
- Nightly Recharge sleep and recovery analysis
- Life Log activity tracking (steps and calories)
- Running and interval training modes
The shift to a ‘GM’ (G-Shock Metal) designation suggests the watch will be aimed at users who want the utility of a fitness tracker but prefer the aesthetic of a traditional metal timepiece.
While Casio has not officially confirmed the device, its appearance in certification filings usually precedes a public announcement by three to four months. So, we’ll keep an eye out.
The Wareable take
The DW-H5600 was a hit for G-Shock purists, but its resin build always made it look like a gym accessory. A Full Metal version with the same Polar smarts is exactly what the community has been asking for.
Casio’s strategy of using Polar’s algorithms also lets them focus on what they do best—indestructible design—while letting someone else handle the complex data science.
This could be the brand’s best hybrid yet, and one that’s comfortably a smarter device than last year’s barely-smart MW-8 for the G-Shock GD-B500 series.
