Columbia Lighting LHA4-654-NST-24EPU LHA Industrial Fluorescent High Bays Compact, open body linear high bay offers energy efficient performance Easy center-ballast cover allows tool-less access without lamp or reflector removal Extremely low profile - only 2 inch overall height allows fixture to be installed without concern about obstructions Reflector options include up light (recommended) or solid top with either narrow or wide distribution Rotary locking lamp holders secure lamp in position and conceal contacts