Smartwatches are tiny. And with such a limited space, engineers have to design a device packed with many smart features while not straining the battery which also has to be small. While most manufacturers rate their smartwatches to last about a day or so, the Amazfit GTR 3 is a different kind of beast.

It’s a properly working smartwatch equipped with a satellite navigation system, heart rate sensor, blood-oxygen saturation, breathing rate, voice assistant, and over 150+ sports modes to suit your choice of activity. Despite these advanced features, the GTR 3 manages to offer up to 21 days of battery life. A number that is really hard to find for smartwatches.