Dish DVR Cooling Fans for VIP 722/622/922/612, with thermoswitch & Multi-Speed Control This cooling system is designed to mount on the side of your Dish VIP DVR, over the left air vents. It will quietly pull the hot air from the chassis and exhaust it out the side. The system has a thermoswitch, which turns the fans on and off as needed. This temperature has been carefully selected to match your Dish DVR. The fans will stop after the DVR has cooled down. It has 2 high-quality, low-noise 80mm fans, with super-quiet Fluid Dynamic bearings. The fans are combined into a raised air-chamber base, which allows the fans to pull air from all your DVR's side vents over an area of 9-3/4" x 3.5". In addition, you control the speed of the fans, with the multi-speed power controller. Recommended fan speeds for this system: The two fans (running together) are rated at 13db while moving 31 cubic feet of air per minute at 1/2 speed, or 16db & 41CFM at 2/3 speed. With component cooling, slow (and quiet) are the way to go! Other available speeds: 1/4 speed = 10db/16CFM, 3/4 speed = 19db/46CFM, full speed = 22db/62CFM. The DVR fan unit is 9-3/4" wide, 3.5" tall, and 1.5" deep (including the top grill and air-chamber base), and only requires 1/4" of space outside the fans for air flow.