Quasar Science Q50-X Crossfade Overview The Q-50X Crossfade Linear LED Bi-Color Light from Quasar Science is a 50W linear LED tube with an expanded bi-color range of 2000-6000K. The lamps can be stacked in large, custom-configured arrays, and may also be used to retrofit existing Kino Flo light units. Self-Ballasted No need for external power supplies or ballasts Dimmable Compatible with most dimming systems, flicker-free through entire dimming range UPC: 768480722514