I have purchased mi band 4 in last month by amazon . I thinks that xiaomi is a good company so I buy it but after some days using the watch I noticed that its battery drains so fast and its syncing with app is also so difficult my phone not shows its Bluetooth connection near me its a connection problem and and after charging it full it only give you not so much battery backup I am totally disappointed with this watch it is a total waste of money and when I go to ask about the problem in store it costs me more and its inside problem not be full recovered and its charger is also of a very bad quality it takes many time to fully charge the mi band4 I think that buying this watch is a total waste of money and its band also of not good rubber quality it starts disturbing my hand .