This is a Sylvania branded 34 -Watt, T12 rapid start Super Saver fluorescent lamp. Deluxe Cool White phosphor with 4100K color temperature and 87 CRI. This replaces F40T12 RS lamps. 20000 Avg rated life at 3 hours/start, 28800 Avg rated life at 12 hours/start. VIVID Color: High CRI lamps for color critical applications.