Mi band 2 is the best budjet oriented band currently available at the given price range. Literally they are amazingly accurate in calibrations and measurement . With a good battery life of around 20 days. It has step count and heart rate monitor. Now it has improved a lot as compared to its prior model which deprived of a display. They have also I.proved sensors and other specs. With this band you can monitor your sleep and heart rate. one more thing amazing about the band is that they are ip67. Splash proof so you don’t have complete water resistance but still it’s good as compared to other smart bands at this price point