Description Features: 100% brand new and high quality Cable length: about 30cm / 11.8inch. Connector: One is USB port, another one is small 3 pin / 4 pin case fan power adapter cable port. Fan must have a start voltage at or below 5V (fans with a higher start voltage will NOT work), 12V fans will be operated at a reduced 5V voltage for silent operation. Function: This cable is 5V USB port to small 3-pin / 4-pin fan cable with switch, it allows you to power most case fans by using a USB connection, 3pin or 4pin case fan power adapter cable both OK, you can turn on/off any time by switch. You can use this line to supply power to the chassis fan by computers USB port, or DIY the chassis fan to modify the notebook cooling pad fan. Package Includes: 1PC x Cable Specifications: Product name: Big 4pin to USB switch cable Length: approx. 30cm/11.81in Wire model: 2464 22AWG Insulation material: PVC Conductor specification: 17x0.14TS Conductor material: pure copper Wire outer diameter: OD3.5mm Rated temperature: 80 Colour: Black Interface: a large 4pin connector at one end, and a USB interface at the other end Function: Change the chassis fan to USB interface for power supply note: The fan must Have a Start Voltage of or less than 5V (fans with a higher start voltage will not work). Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you