HP RU5-0389-000CN gear is a replacement part for the LaserJet 2400 Series. The service manual identifies this exact part number as a gear, making it useful when servicing the printer’s drive mechanism.
Its distinguishing specification is 201 teeth. The part is described as a large, white plastic gear positioned on the right side of the printer. These details help identify it among the printer’s other gears when sourcing a matching service part.