I am using this band from 3rd may of 2016 & was so happy to see its performance, Battery backup is awsome Company says that its battery backup is of 30 days. But I was surprised to see that this band last long for 38 days. This band tells us the deep sleep during night and about light sleep.
It is very easy to use& fully worth of money.This band is so stylish and looks very beautiful in hand.this band records whole day data and when I connect is to my phone then it sync whole day data to my phone.