If you have a set of Corsair Dominator DIMMs, then the Corsair AirFlow 2 and Airflow Pro are for you.  The Corsair AirFlow 2 adds a shroud and two fans to actively cool your DIMMs.  Add in the Airflow Pro on top and in addition to the extra cooling, LEDs will add a bit of spice to your system and will even give you information on load and temperature.   Legit Reviews can tell you all about them.

"We observed a 8C temperature decrease at idle and a 12C decrease at load with the DDR3 clock frequency set to 1600MHz. In the end the Corsair AirFlow 2 memory cooling solution proved to be worth it. If you have a tight case with a lot of hot components and limited airflow using the Corsair Airflow 2 is a really good idea…"

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