The Middle Atlantic Fan Top with 10 Fan Mount for ERK or SCRK Racks (Black) will increase your rack's functionality by adding 3, 4.5 fans to the top of your rack, increasing equipment circulation and air flow. Middle Atlantic's 2 rack space, aluminum service plates are made to fit perfectly with your existing ERK or SCRK rack system and blend seamlessly into your work environment. Features: The three 4.5 fans feature a proportional speed thermostatic fan control that runs the fan only run when its necessary. This extends the fan life, reduces noise and maintenance requirements.