LB1 High Performance New Super Cooling Fan for Apple MacBook Air Core i5-2557M Dual-Core 1.7GHz 4GB 128GB SSD 13.3" LED Notebook AirPort OS X w/cam & BT MC965LL/A Aluminium Cooling Fan Cooling System Cooling Pads with 3 Fans and 4 USB Ports 3 fans provides extreme air flow. High thermal heat dissipation prevents overheating . Great ergonomic shape for simple typing. Support low noise. Slim and Smart design. Helps notebook to operate at full speed even while running high performance applicatis. Lightweight and compact - Perfect for portable user. Powered by 1 USB cable. Plug-and-play: no drivers or software needed. Rated Voltage: DC 5V. Speed: 1500-2300 RPM. USB Port: 4. Dimensions: 11.8 x 9 x 0.5 inches.