1. High quality Portable Laptop/PC USB Cooler Cooling Fan. 2. Ultra-quite design, Super mute, with key switch. 3. Pitch angle can be adjusted upwards or downwards. 4. USB Powered, no external power required. 5. Plug and play, easy install. 6. Durable soft fan blades make you free of injury. 7. USB transformer can be purchased on its own power supply ,the proposed purchase of 5V ,1000MA transformer above.