A few months after it was launched in China, the Mi USB Fan from Xiaomi is now available for purchase in India. The device carries a price tag of INR 249 (around $4), and can be purchased through the Chinese company's online store - mi.com/in.
As you can see in the image above, the device basically consists of a USB cable with motor and detachable fan blades. You can plug it into your laptop's USB port, or a USB charger, or even a compatible power bank.
Xiaomi claims that the device can work for 21 hours when attached to the company's 5000mAh power bank, 38 hours when plugged into a 10400mAh power bank, 62 hours with 16000mAh power bank. It is also claimed to make only 25.8db of noise.
The fan is available in both white and blue colors.
dont use simple maths,open any electronics engineering book and read it, its collatral damage
to remind you that this "news" is in blog page as ten years reader of gsmarena, in blog page they write about everything outside phone news
If it runs for 21hrs with 5000mah then it is supposed to run around 42hrs with 10400mah, right?