The updated tracker comes with an optical heart rate sensor built in, but the company has managed to keep the price extremely wallet-friendly. The Mi Band 1S, light-sensitive version, is available from 11 November for 99Yuan, that's about $16.
The original Mi Band has seen its price cut as a result to 69Yuan. There's no word on a release outside of China as of yet.
Wareable guide: Best fitness trackers you can buy
The 1S hasn't changed all that much in terms of design from the original, with the module setup still in place, but the heart-rate tracking has added an teeny bit of bulk.
The original measured 36 x 14 x 9mm; the new tale of the tape is 37 x 13.6 x 9.9mm. It's only half a gram heavier though, weighing in at 13.5g.
Xiaomi's new Band will track a user's heart rate, in real time, using photoelectric light perception and it also handles the regular fitness tracker functions such as step counting and sleep monitoring.
The battery is the same 45mAh one that provided a 30 day lifespan in the original. Expect a few days less thanks to the new heart rate features.
The Mi Band 1S is IP67 certified dust and water resistant and also offers users a phone unlock feature and incoming call alerts by way of a vibration motor.
Sales of the Mi Band have escalated rapidly in the last 12 months or so. The fitness tracker, previously only available in the company's homeland, is now on sale in the western world and can be picked up for a ridiculously low $15. It's been reported that as many as 6 million devices have now been sold around the world.
In our Xiaomi Mi Band review we stated it's far from perfect but would be a great starter tracker for anyone not sure they are ready to take the plunge with a Fitbit or Jawbone, just don't expect too many bells and whistles.
Check out our pick of the best budget fitness trackers to see what the 1S is up against.
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