Features: brand new and high quality Effectively reduce fan noise. Let you no longer endure the noise of the CPU. The effect is good! At the same for time, it can prolong the service life of the fan. It can achieve the effect of extending the power cord of the fan, which can be said to serve multiple purposes. Easy to use, one end is connected to the power cord on the fan, and the other end is connected to the power interface of the fan on the motherboard. Specifications: Name: CPU 4pin down speed line Material: Copper Length: approx. 12cm/4.72in Interface: standard 4 needle (male for head -- female for head) Package Includes: 1PC x CPU 4pin down speed line note: The resistance of the deceleration line will heat up when it is working, which is a normal phenomenon Professional 4P fan silent speed reduction line, through the principle of connecting a resistor in series, to reduce the fan voltage, thereby reducing the fan speed. Applicable to any fan with 4pin interface, it is OK to connect it in series between the fan and the fan interface.