Plasma & LCD TV cooling fans with 12 volt trigger & multispeed control /12v trigger 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 has a 12 volt trigger control module, which turns the fans on and off, by monitoring your receiver's 12v trigger socket. This module sends power from the multi-voltage transformer (included in the system), which runs the fans. IMPORTANT: Some receivers have a non-standard setup, where the receiver doesn't directly control the trigger (for example, the trigger might be under the control of Zones 2 or 3, etc.). Please consult your receiver's manual for details about how its 12v trigger operates, or contact me if you have questions. 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. The fan units are connected by a 2-way power distribution cable, which allows you to separate the fans by up to 7 feet apart.