(1)The Extended Rear Panels provide more depth and ventilation than standard rear panels, are easily removed for quick component access, and are constructed of heavyweight powder-coated steel. (2)The Extended Rear Panel with Active Cooling Kit prevents heat buildup inside the cabinet. It employs a remote thermostat and dual, maintenance-free fans for precision cooling. The rear panels are easily removed for quick component access, and constructed of heavyweight black powder-coated steel with ventilation louvers.