Type D LED Ubends, sometimes called Type A/B, can work on the existing ballast (if compatible) or can bypass the ballast and wire direct. This gives users the flexibility to use the rest of their ballast, and once the ballast dies out they can wire the lamps direct. Available in 3500K, 4000K and 5000K color temps and in the skinny Ubend 1-5/8" or the standard 6" spacing.