... use,Home use.. ModelQT-U401ASpecifications:4-inch, 1 speed governorMaterial:Metal - ironType:spray powderPlug:USBMotor:BrushlessVoltage:5VPower:2.5WCord Length:1 ... power cord (supply) to connect PC to start the fan.The fan can be used in camping,travel,home,office,school,hospital ... and flexible ; Brushless DC motor, durable and ultra-quiet. USB Fan