Sylvania 55W T5 Pentron Circline Fluorescent Bulb - FPC55/835/HO - Description: 55W, T5 Pentron Circline High Output (HO) fluorescent lamp, 3500K color temperature, rare earth phosphor, 82 CRI. Average Rated Life (hr) 12000, Base 2GX13 Bulb T5, Manufacture Sylvania. Part number Sylvania-20750 Sylvania 55W T5 Pentron Circline Fluorescent Bulb - FPC55/835/HO