Filler Panels are used to control the air flow inside of server racks. Without the use of filler panels, the hot exhaust air from the servers can be recirculated through the server and significantly reduce the cooling efficiency of the system. Installations that have Open Frame Racks, closed Server Cabinets, or a 2Post Rack can benefit from the use of filler panels. In any installations, the filler panels also help give your rack a clean and professional look. Compatible with all EIA Standard 19" racks and cabinets with square holes including Dell, HP, Compaq, IBM, APC NetShelter, APW, Liebert, CPI Chatsworth, Rittal, Blackbox and many others.