Fixture Highbay LED T8 (4) Lamp Ready Designed to create a complete UL-listed fixture by the most economical means, The lamp ready series as a companion to our internal driver LED Linear T8 replacement lamps, direct wire 120 or 277V. Lamps must be purchased separately. This lamp will only operate single end power direct wire LED tube lights. The fixtures allow installers to avoid bypassing the ballast and adopt the energy-saving benefits of LED technology while keeping the product UL listing intact.