HP (Hewlett Packard) Color LaserJet 2550N (Q3704A) is a multi-pass color laser printer manufactured by HP for both home and office use. Laserjet 2550N prints up to 4 ppm color, 20 ppm black with resolution 600 x 600 dpi. HP Color LaserJet 2550N uses HP (Hewlett Packard) Black 122A and three Color 122A 123A Cyan, Yellow, Magenta cartridges. Cartridge model numbers are Q3960A, Q3961A, Q3962A, Q3963A, Q3971A, Q3972A, Q3973A. HP (Hewlett Packard) Color LaserJet 2550N also uses one imaging drum unit with part # is Q3964A.