Xiaomi first Fit Band. It is 30 mm height, 14 mm width and 9mm thick. There is no display but it have 3 multicolour LED covered by aluminium surface. The colour can be change to white, blue, etc. It have ultra thin 8mm lithium ions battery and its capacity is 41mAh. One full charge can last you to 30 days. You can sync your data to you smartphone through MI Band app with bluetooth. You can see your calories burn, distance you traveled and stepps you walked. It is water resistance. It have mi band smart alarm and wake you up 30 minutes before the alarm goes off. You can locate your mi band by turn on light and vibrate as long as it is in the bluetooth range through MI Band App.