It was purchased to replace the battery of a Samsung S3 Frontier, which didn't even turn on after 2-3 years of continuous operation.
It seems to be the same as the original, and the smartwatch worked immediately, with the same battery life as when it was first purchased.
However, the price of around 28 euros seemed a bit high to me, hence the 4/5 stars.
The smartwatch is barely worth 60-70 euros after so many years.
Also, very few stores had it, and I'm not sure if it will still be available after another 2-3 years.
So, logically, the lifespan of a smartwatch, if you can't find batteries for replacement more than once, is limited to 4, maybe 5 years, which is not much for a watch, even a smartwatch.