Fan tray system lets you locate fans directly above vents on hot equipment to help hot air get moving in the right direction for rack cooling systems. Uses from 3 to 8 quiet 4in DC fans (69 CFM for each fan). 8 fan mounting positions and optional add-on fans let you locate fans exactly where needed. Energy-saving thermostatic control for automatic on/off as needed. Powered by a single power cord. Occupies only one rackspace. Adjustable mounting range of 18in to 32in. Locates fans directly above hot equipment to promote air flow. Tray can be adjusted on mounting rails as needed. Fans can be located in best positions for project needs. Additional fans can be added, up to a total of 8. Includes power supply and thermostatic controller. Includes three fans (69 CFM per fan).