Kospet Tank M4 Review: A rugged smartwatch optimised for iPhone
The Kospet Tank M4 is a rugged, iPhone-optimised smartwatch with excellent battery life, strong fitness tracking and seamless Apple Health integration that delivers premium features at a fraction of flagship smartwatch prices. Picture: Michael Sherman/IOL
Image: Michael Sherman/IOL
I’ve been using the Kospet Tank M4 since the beginning of January and, despite never having heard of the brand before being offered one to review, it has quickly become my favourite smartwatch.
That praise doesn’t come without caveats.
There are a few irritations worth addressing upfront, some of which may come down to personal preference. For example, though it has a massive 30GB of storage, it takes incredibly long to copy music over from your phone to the watch, and if any music file is over 100MB, it will eventually fail every time.
However, the Tank M4 delivers far more than its price tag suggests.
Built Like a Tank — For Better or Worse
The name isn’t marketing fluff. The Tank M4 is heavy. Really heavy. It took time to adjust to wearing a watch this substantial since its body is made from durable stainless steel, especially coming from a lighter plastic Garmin running watch. Once I stopped making that comparison, however, the weight became a non-issue.
This rugged build makes sense when you consider that the M4 is billed as a diving watch, and durability is clearly its core design focus. It’s not a fashion-first smartwatch — it’s built to survive punishment.
Fitness Tracking That Mostly Delivers
Despite its size, I’ve used the Tank M4 successfully on all my runs. Accuracy has been on par with other smartwatches I own, and GPS tracking has been reliable.
That said, there are some frustrating omissions. I’m yet to work out how to get the watch to notify me — via vibration or sound — at each kilometre marker during a run. For someone pedantic about pacing, this is incredibly annoying, especially since most smartwatches enable this by default.
Some activity settings are also buried deeper than they should be, making customisation less intuitive than rivals like Garmin or Apple.
Seamless iPhone Integration Is the Real Win
Where the Tank M4 truly shines is iPhone compatibility.
The user interface will feel familiar to anyone who’s used Huawei watches running HarmonyOS, such as the Watch Fit 3 or Watch 4 Pro, but here it’s fully customisable and — crucially — plays nicely with Apple’s ecosystem.
I was able to:
• Sync workouts seamlessly with Strava
• Automatically feed data into Discovery Vitality
• Reliably update Apple Health metrics on iPhone
That last point is especially important. Huawei devices still struggle to integrate with Apple Health without third-party workarounds, and the Tank M4 handles this without fuss.
Health metrics include heart rate monitoring and blood oxygen levels, and there’s a handy bonus feature: the watch can act as a remote shutter for your iPhone camera, which is surprisingly useful.
Customisation and Battery Life Impress
The watch features four physical buttons — two on each side — alongside a responsive touchscreen. Navigation feels logical once you’ve spent a bit of time with it.
Customisation is handled through the Apexmove app on iPhone, which offers a huge selection of watch faces and themes. I settled on a clean, high-contrast design called Simple Thrive, using white and light orange accents.
While some watch faces cost R19.99, the majority are free, and there’s little incentive to pay extra.
Battery life is another standout. Over a measured week, which included two 45-minute runs, the Tank M4 used just 39% of its battery — an excellent result for a feature-packed smartwatch.
Price and Availability in South Africa
The Kospet Tank M4 was only released in November, so availability in South Africa is still limited. That said, I managed to find it online for R3,274.99 without much effort.
At that price, the value proposition is hard to ignore.
Verdict: Punching Well Above Its Weight
From what I’ve seen, the Kospet Tank M4 punches well above its price tag. If I were in the market for a high-end smartwatch, this would be near the top of my list.
In fact, I’d go as far as to say it’s comparable to the Apple Watch Ultra 3, which costs around R19,499 — a massive price gap for a surprisingly small drop-off in everyday functionality.
It may not have the brand recognition of Apple, Garmin or Samsung, but the Tank M4 proves that lesser-known names can still deliver exceptional value — especially for iPhone users who want rugged durability without paying flagship prices.