... fan,laptop fan,usb fan,mini fan,desk fan 1.4 inch usb fan 2.Rotational speed 2500prm,5V/12W ... mini usb fan, portable usb fan, 4" portable fan, cooler fan, USB fan, desk fan Brushless motor make it lower noise, stronger wind ... useSize of item4 inchSize of Unit15×9.5×16cmMotor materialDC Brushless motorSpeed settingRotational SpeedAutomatic2500~3000 rpmBlade96mm aluminum bladeGrillSafety metal line ...