- most important: a sync feature (for example with a basestation at your home) that does NOT give up your personal health data to the manufacturers server, which in term will sell your data to health insurance companies and what not.
- standalone operation, not a dumb device that needs a bluetooth tethered smartphone near it all the time
- buttload of sensors, like pulse, oxygen level, blood pressure, odometer, body/outside temperature
- battery run time in the region of weeks or months
- physical buttons on the front, not side. if it has an laughable stamp-sized touchscreen i am not going to buy it
- waterproof, not water resistant