Optimally designed pure copper fins effectively disperse heat away from the CPU via heatpipes, while the high capacity 120mm fan quickly cools the heatsink for stable operation of high performance CPUs. The PWM (Pulse Width Modulation) Fan automatically adjusts fan speed (RPM) according to the CPUs temperature, ? while the included Resistor Cable (RC33P) provides the option of reducing the input voltage for overall reduction of fan speed & noise. An ultra quiet 120mm fan is incorporated for minimized noise & Blue LEDs heighten the cool aesthetics The CNPS9900A LEDs distinctive Omega (?) design not only provides excellent CPU Cooling but also effectively cools surrounding components for excellent system stability. The included all high performance thermal grease ZM-STG2 maximizes heat transfer from the CPU to the base of CNPS9900A LED for intensified cooling performance. Compatible with Intel LGA1366/1150/1155/1156 & AMD FM1/AM3+/AM3/AM2+/AM2/939/940/754