General description Powerful 5V Nano Cooling Fans designed for efficient cooling with PWM speed adjustment. Each fan features a 4PIN anti-reverse connector for easy installation and reliable performance. Technical specifications Voltage: 5V Connector: 4PIN anti-reverse Size: 40x40x20 mm Material: Plastic Package Contents: 10 Cooling Fans Other information Note: Light reflection and different displays may cause the color of the item to differ slightly from the real thing. The measurement allowed error is +/- 1-3 cm.