The Color Proofing Light Kit has everything you need to do your proofing at your work station area. The kit includes: Four SoLux Black Back (3500K, 4100K, 4700K, 5000K (50K)) 36 degree lamps, four track fixtures, four foot section of track, and a power-feed with cord. Tailored Lighting Inc. put (D50) in parentheses to highlight the fact that SoLux 5000K is the closest simulation of D50 on the market bar none.