The present invention provides a system that allows for a single panel of the invention to be easily modified, preferably without the use of tools, to fit on a server rack, where the single panel is so modified as to cover the desired amount of open space on a server rack as a single piece, where the panel is preferably fire-rated, and where the modified panel may be easily installed onto the server rack to as to cover any open space thereon, and prevents the circular flow of warm air output from entering the cooler air input of the servers housed on the server rack.