This SmartDevil USB gadget is a must-have for all computer owners! Based on our own experience, it is small, portable and super easy to use.The adjustable fan speed is a great feature keeping our computers cool during hot summer months. The rechargeable battery lasts for a long time and it can be recharged with a USB cable. The only con we have found is that it can be a bit noisy at maximum speed. Overall, we highly recommend this little gem to anyone who wants to keep their computers from overheating..