First, I promise this will be the last Xiaomi product deal promoted for a while...
A bit of a throwback to when Xiaomi released the original Mi Band, and yes, i'm ok.
Since then Xiaomi has gotten consistently better, matching up to what you'd expect to see from Fitbit and others.
The latest Mi band in the series is on special at ebay and comes with a good set of features, and a nice OLED display.
The Mi Band runs Android wear, and has a good batter life for something with heartbeat tracking and an OLED screen. Check out the product description on ebay!