A toner cartridge, comprising: a housing having a top, a bottom, a first side and a second side positioned between a first longitudinal end and a second longitudinal end of the housing, the housing has a reservoir for holding toner; a photoconductive drum rotatable relative to the housing, a portion of an outer surface of the photoconductive drum is positioned along the bottom of the housing, the photoconductive drum includes a rotational axis that extends in a direction from the first longitudinal end to the second longitudinal end; a developer roll rotatable relative to the housing and positioned to supply toner from the reservoir to the photoconductive drum; a first drive coupler and a second drive coupler on the first longitudinal end of the housing for mating with a first corresponding drive coupler in an image forming device and a second corresponding drive coupler in the image forming device for receiving rotational motion from the first corresponding drive coupler in the image forming device and the second corresponding drive coupler in the image forming device when the toner cartridge is installed in the image forming device, the first drive coupler of the toner cartridge is operatively connected to the photoconductive drum to transfer rotational motion to the photoconductive drum and the second drive coupler of the toner cartridge is operatively connected to the developer roll to transfer rotational motion to the developer roll; a first positioning slot on the first side of the housing for receiving a first corresponding positioning rib in the image forming device for defining an axial position of the photoconductive drum relative to the image forming device along the rotational axis when the toner cartridge is installed in the image forming device, the first positioning slot extends upward from the bottom of the housing near the second longitudinal end of the housing; and a second positioning slot on the second side of the housing for receiving a second corresponding positioning rib in the image forming device for defining an axial position of the developer roll relative to the image forming device when the toner cartridge is installed in the image forming device, the second positioning slot extends upward from the bottom of the housing near the second longitudinal end of the housing. a housing having a top, a bottom, a first side and a second side positioned between a first longitudinal end and a second longitudinal end of the housing, the housing has a reservoir for holding toner; a photoconductive drum rotatable relative to the housing, a portion of an outer surface of the photoconductive drum is positioned along the bottom of the housing, the photoconductive drum includes a rotational axis that extends in a direction from the first longitudinal end to the second longitudinal end; a developer roll rotatable relative to the housing and positioned to supply toner from the reservoir to the photoconductive drum; a first drive coupler and a second drive coupler on the first longitudinal end of the housing for mating with a first corresponding drive coupler in an image forming device and a second corresponding drive coupler in the image forming device for receiving rotational motion from the first corresponding drive coupler in the image forming device and the second corresponding drive coupler in the image forming device when the toner cartridge is installed in the image forming device, the first drive coupler of the toner cartridge is operatively connected to the photoconductive drum to transfer rotational motion to the photoconductive drum and the second drive coupler of the toner cartridge is operatively connected to the developer roll to transfer rotational motion to the developer roll; a first positioning slot on the first side of the housing for receiving a first corresponding positioning rib in the image forming device for defining an axial position of the photoconductive drum relative to the image forming device along the rotational axis when the toner cartridge is installed in the image forming device, the first positioning slot extends upward from the bottom of the housing near the second longitudinal end of the housing; and a second positioning slot on the second side of the housing for receiving a second corresponding positioning rib in the image forming device for defining an axial position of the developer roll relative to the image forming device when the toner cartridge is installed in the image forming device, the second positioning slot extends upward from the bottom of the housing near the second longitudinal end of the housing.