Thermaltake CL-P0191 Silent Cooling Solution for Intel BTX & Micro BTX Form Factor (Type I) Designed for BTX & Micro BTX Form Factor (Type I) Heatsink with aluminum fins soldered to copper base Dual-heatpipe facilitate the transmission of heat 4th pin of the fan connector has PWM and thermal control function Noise Elimination Sponge absorbs the entering noise from the airflow