Summary USB plug: USB plug can power the fan via USB ports behind popular AV electronics and game consoles. Two dual ball bearing: Dual-ball bearings can work 67,000 hours and allows the fans to be laid flat or stand upright. Certification: Brushless cooling fan is certificated by UL and CE, it is very safe, UL CE brushless fan can provide you large air flow; low noise; long service life; good running stability and corrosion resistance. Compatibility: Brushless DC fan for computer case, 3D printer, for humidifier, aromatherapy and other small devices, small heat radiation, communication equipment, military equipment, intelligent industrial control equipment, high precision medical equipment, PC CPU server cooling, electronic cooling fans and so on. Multiple protection: Metal grille on both sides to prevent hand injuries and cable damage from the blade, cable protection glue in the corner, wear-resistant and not easy to break. 2pcs USB Plug 3D Printer 4010 Brushless Cooling Fan 5V DC Dual Ball Bearing Description USB plug: USB plug can power the fan via USB ports behind popular AV electronics and game consoles.Two dual ball bearing: Dual-ball bearings can work 67,000 hours and allows the fans to be laid flat or stand upright.Certification: Brushless cooling fan is certificated by UL and CE, it is very safe, UL CE brushless fan can provide you large air flow; low noise; long service life; good running stability and corrosion resistance.Compatibility: Brushless DC fan for computer case, 3D printer, for humidifier, aromatherapy and other small devices, small heat radiation, communication equipment, military equipment, intelligent industrial control equipment, high precision medical equipment, PC CPU server cooling, electronic cooling fans and so on.Multiple protection: Metal grille on both sides to prevent hand injuries and cable damage from the blade, cable protection glue in the corner, wear-resistant and not easy to break.