OPTIMUM LIGHTING U21-1054-HV-3PS-E-QC-C6P-841 4' 10 LAMP T5HO OPEN HIGH BAY WITH WIDE LIGHT DISTRIBUTION AND UP LIGHT COMPONENT. PROGRAM START BALLASTS (480V); ENHANCED SPECULAR REFLECTOR; 4100K F54T5/841/HO/ALTO T5HO LAMPS W/6'CORD & PLUG, QC 10' QUICK HANG KIT