USB to 4-Pin Molex 5V Fan Power Cable This Cable Allows You To Power Most Case Fans Using A USB Connection Cable Length (Including Connectors): 39" 12V Fans Will Be Operated At A Reduced 5V Voltage For Silent Operation Fan Must Have A Start Voltage At Or Below 5V NOTE: This Cable Was Only Designed For Powering Molex Case Fans At 5V, Other Uses Are Not Officially Supported