Philips LED T8 U-bend, 15.5 Watts, 3500K, 535542. The CorePro MainsFit (UL Type B) lamps are designed to be the perfect retrofit solution to move from traditional fluorescent lamps to energy saving LEDs. This ballast bypass lamp has everything needed built into the lamp with proven energy savings, long life (up to 50k hours), surge suppression and industry leading safety features. All lamps in the CorePro MainsFit family are double-ended to help simplify the installation. In addition, all lamps meet the Philips standards for light quality so that end users will be in a comfortable environment regardless of the CorePro MainsFit lamp type