Sylvania 40W T5 Pentron Circline Fluorescent Bulb - FPC40/830 - Description: 40W, T5 Pentron Circline fluorescent lamp, 3000K color temperature, rare earth phosphor, 82 CRI. Average Rated Life (hr) 12000, Base 2GX13 Bulb T5, Manufacture Sylvania. Part number Sylvania-20731 Sylvania 40W T5 Pentron Circline Fluorescent Bulb - FPC40/830