Plasma & LCD TV Vertical-Mount Cooling Fan System, with USB-Control & multispeed Fans This cooling unit is designed to quietly pull hot air out of your TV or video monitor. It has 2 high-quality, low-noise 120mm fans, with long-lasting and quiet fluid dynamic bearings. Each fan has a mounting plate, with a rubber air-chamber ring around the bottom edge, to make sure the fan is sealed against the back of the TV. The fans are also fitted with snap-lock adhesive pads, which stick the fans to the back of your TV, yet allow easy removal and reinstallation. The system includes a USB control module, which turns the fans on and off, under the control of your TV's USB port (type A connector). The USB module controls the power from the multi-voltage transformer (included with the cooling system), which runs the fans. In addition, YOU control the fan speed, using the multi-speed fan controller. IMPORTANT: Please make sure that your TV's USB port turns on (powers up) ONLY when the TV is turned on. That way, the fans will run when the TV is on and turn off when the TV is off. Recommended fan speeds for this system: The fans (running together at 2/3 speed) are rated at 19db while moving 98 cubic feet of air per minute, or 22db & 110CFM at 3/4 speed. With cabinet cooling, slow (and quiet) are the way to go! Other available speeds: 1/3 speed = 13db/50CFM, 1/2 speed = 16db/72CFM, Full speed = 25db/148CFM. Each cooling unit measures 5-1/2" square (includes the mounting plate). The units are 1-1/4" tall, and only requires about 1/3" additional space for airflow.