Philips FlexFit (Hybrid UL Type A + B) lamps are designed with the customer in mind for installation flexibility. The FlexFit lamp can operate as both a plug and play (UL Type-A) and double-ended direct wire (UL Type-B). As with all Philips products, the FlexFit family of lamps are compatible with more ballasts than any manufacturer giving the customer peace of mind during installation. Additionally, the long life (50K hours) delivers reduced maintenance and replacement costs. If the ballast should fail, simply cut the ballast from the system and wire the tube directly to line voltage (120-277V)!