Fitbit Sense Advanced Smartwatch is a very interesting smartwatch with loaded features and apps. The watch comes with an ECG app for any irregularity of your heart rhythm, but this feature is not available in all countries. You also get a SpO2 monitoring system which is used for Oxygen monitoring. You get 6+ days of battery backup, the smartwatch has an activity monitoring feature which is useful to optimize the usage of your watch. The watch has a built-in microphone which can be used to answer calls right from your watch. The watch is waterproof with a max depth of 50 meters.