This Philips 13989-9 shatter resistant F32T8 linear fluorescent tube operates at 25 watts. It has a medium bi-pin base, color temperature of 4100K, and an average life of 36,000 hours. The P.E.T. coating around the tube has U.V. protection against yellowing, fading, and clouding. It is extremely strong, puncture resistant, and lightweight. These fluorescent lamps are perfect for any residential or commercial application. Case contains 25 lamps.