Cartridges may include a developing roller, an electrode, a detection member, and a cover member. The developing roller rotates about an axis extending along a first direction. The electrode includes a protrusion that protrudes along the first direction to an end portion. The detection member includes a cover portion, which covers an exposable portion of the protrusion when the detection member is in a first position, and which exposes the exposable portion of the protrusion when the detection member is in a second position. The cover member covers a portion of the detection member and exposes the cover portion when the detection member is in the first position. The cover member extends in the first direction to an end portion. An overlap portion of the protrusion extends at least to the end portion of the cover member and overlaps a portion of the cover member in a second direction.