From MIUI Official Forum:
Today Xiaomi unveiled Mi Band 2 with OLED display which displays Time, Steps Count and Hear Rate at just RMB 149 (US $23). It will be available for sale from 7th June, 2016 onwards in China.
The Mi Band 2 is more expensive than its predecessors, but it’s also a bit fancier. The tiny black-and-white display displays time, your step count, your heart rate, as well as approximative distance and calorie counters. You can also use the device to monitor your sleep. Nothing groundbreaking if you’re familiar with activity trackers.
I think I want one.