The Arctic P14 PWM PST 140mm Black Case Fan (ACFAN00138A) is optimized for static pressure, making it ideal for use on heat sinks and radiators. It features a 0 dB mode for silent operation, a more efficient motor that saves energy, and a maximum quietness and minimum vibration design. With a wide range of regulation and PWM Sharing Technology, this fan can be controlled synchronously with other fans for maximum cooling performance. This 5-pack includes five fans, backed by a 6-year manufacturer's guarantee, perfect for upgrading your case or radiator cooling.