Introducing FlexFit (Dual-mode) T8 LED Lamps by Philips. It works as either a plug-and-play (UL Type A) or ballast bypass (UL Type B) lamp. As a Type A lamp, it is compatible with a variety of electronic ballasts. If a ballast is not desired or fails in the field, the lamp can quickly be installed as a double-ended ballast bypass (UL Type B) lamp.