Ready-to-install, low-profile (2-inch D) rear door panel has two whisper-quiet fans (4.7-inch diameter, 100cfm total airflow, 31dBA), fan guards and detachable 6ft cord. Panel mounts to rear door vent pattern of Lowell rack series LGR, LER, LPR, LPPR,LSGR, and LSER. Assembly typically mounts inside rack rear door to exhaust warm air out the back but it can also be mounted to the outside of the door.