Genuine W550R, PP749 Dell Alienware Area 51 Liquid/Water Cooled Cooling CPU Heatsink Compatible Part Numbers: W550R (Heatsink Assembly), PP749 (Fan) Genuine Dell Alienware Area 51 Liquid Cooled CPU Heatsink Liquid cooling system CPU heat exchanger with integrated pump Copper CPU Cooling Plate/ Includes: Retainer Ring, Fan, Radiator and In tact thermal grease Large radiator for fast heat dispersion Compatible with Alienware Area 51 System/ Dell Part Numbers : W550R (Heatsink Assembly), PP749 (Fan)