Overcome motherboard limitations with this manual fan controller, ideal for high speed fans that standard auto control. Automatically restricts motherboard curves to a user defined or provides full manual duty cycle control from 0-100%. Perfect for PC enthusiasts, workstation builders, and anyone using cooling fans requiring precise speed management motherboard settings. Essential for silencing noisy high speed cooling fans in desktops or excessive where isn't necessary. This speed controller provide regulation specifically suitable for common consumer motherboards and standard 12V 4 pin fan.