BTOOP USB Desk Fan Mini Personal Fan Metal Design with ON/OFF Switch USB Powered for Home and Office, 4" (Blue) This USB fan is perfect for home,office,study,etc It is pwered by a 3.9 ft USB cable,compatible with computers,laptops,power bank and other devices with USB output Occupied small room,smart shape,cool and soft wind,360up and down adjustable Easy to install and use(put it on a stable surface),with control switch on/off Special metal structure design,more stable and stronger.The little children keep this fan away and be carefully