The magnetic roller sleeve carries the toner from the supply chamber (hopper) to the drum. It is recommended to replace the magnetic roller sleeve for better print quality.Our mag roller sleeves are designed to specifications and standards to achieve consistent performance.Mag Roller for HP C4129X.(Sold in 10 packs only)Compatible with:HP C4129X (LaserJet 5000, 5000GN, 5000N, 5100, 5100dtn, 5100tn, Canon FP-300 Micrographics, FP-400 Micrographics, GP-160F, imageCLASS 2200, 2210, 2220, 2250, LBP-1610, 1620, 1810, 1820, 62X, 840, 850, 870, 880, 910)