The XCM core cooler v2 (Twin fans)  can be used with XCM High Speed Air Cooler v2 for greater effiency and power or independently. All other brands of external fans, can only cool the temperature of the Xbox 360's outer surface, but does not cool the temperature of the CPU/GPU; therefore, making them useless to combat CPU/GPU overheating.  XCM 360 Core Cooler v2 directly cools down the core (CPU and GPU) of your 360 console.