AV/Computer Cabinet Mega-Fan Exhaust Fan with Thermostat & Multi-Speed Control This cooling unit is designed to be mounted inside your equipment cabinet or computer desk. It will quietly pull the warm air out of your cabinet and exhaust it out the back or top. It has a high-quality, low-noise 120mm fan, with long-lasting and quiet fluid dynamic bearings. The system also includes a rugged, no-maintenance adjustable thermostat. In addition, YOU control the fan speed, using the multi-speed fan controller. Recommended speeds: the 120mm fan is rated at 16 db at 2/3 speed, while moving 49 cubic feet of air per minute, and 3/4 speed = 55CFM at 19db. The fan has approximately these specs at other speeds: Full speed = 74CFM at 22db, 1/2 speed = 37CFM at 13db, 1/3 speed = 25CFM at 10db (approximate). With cabinet cooling, slow (and quiet) are the way to go! The cooling unit measures 6-1/4 square, by 1-1/2" deep.