Xiaomi's new Mi Band 1s offers a heart rate sensor for less than $16

Xiaomi has taken the wearables market by storm with Mi Band. The unassuming fitness tracker arrived more than a year ago with a price tag shy of $30 but with a feature set that rivals other offerings costing more than three times as much. Thanks to sales of over 10 million units, it has turned the ever-growing Chinese company from the new kid on the block into the third-largest wearables maker.

But, in the time following the launch of Mi Band, Xiaomi's competitors have diversified their lineups, introducing new models with novel features that make it seem a bit dated in comparison. Enter the second-generation Mi Band, called Mi Band 1s.

First, let's get the price out of the way. Unlike its predecessor which joined the wearables market sporting a price-tag of just under $30, the new Mi Band 1s will be available for CNY 99, or about $15, when it goes on sale later this week.

The price is likely to vary depending on the market and the reseller which offers it, but, nonetheless, it makes you wonder whether the premiums commanded by its competitors can be justified by a typical shopper in this segment of the market.

Mi Band 1s is not the most sophisticated wearable around, but it offers a robust feature set and adds an interesting new feature over its predecessor, namely a heart rate sensor. This is typically not available in less-expensive models from more upscale brands like Fitbit or Jawbone, making Mi Band 1s an option worth considering in late-2015.

Mi Band 1s can also track your sleep and physical activity, and syncs with Android and iOS devices. Those who have a compatible Xiaomi-branded smartphone can set their device so it unlocks without a password when a Mi Band 1s is nearby; it also vibrates to let the wearer know of an incoming call.

Battery life seems to be unaffected, with Xiaomi also promising 30 days as with the original Mi Band. The new model is slightly bigger though, coming in at 37 x 13.6 x 9.9 mm and 5.5 g in comparison to the 36 x 14 x 9 mm and 5 g of its predecessor.