A replaceable unit for an electrophotographic image forming device, comprising: a housing having an internal reservoir for storing toner, the housing having a front, a rear, a top, a bottom, a first side and a second side; and a circuit board, the circuit board being mounted on a surface of the first side of the housing, the surface configured to receive a retainer, wherein when the retainer is installed on the surface, a pocket is formed between the retainer and the surface, the circuit board being within the pocket, and the pocket has an opening facing the front of the housing to permit an electrical connector of the image forming device to enter the pocket and mate with the circuit board when the replaceable unit is installed in the image forming device; and the replaceable unit further comprising: an inclined surface portion on outer surface of the first side in front of circuit board, wherein surface portion inclines outwardly and rearwardly from the front toward the outer surface, and a first guide wall and an opposing second guide wall outside the pocket on the surface of the first side of the housing between the inclined surface portion and the opening, the first guide wall positioned closer than the second guide wall to the top of the housing and the second guide wall positioned closer than the first guide wall to the bottom of the housing; and a cam ramp (185, 186) and corresponding support (187, 188) on the surface of the first side of the housing inside the pocket. a housing having an internal reservoir for storing toner, the housing having a front, a rear, a top, a bottom, a first side and a second side; and a circuit board, the circuit board being mounted on a surface of the first side of the housing, the surface configured to receive a retainer, wherein when the retainer is installed on the surface, a pocket is formed between the retainer and the surface, the circuit board being within the pocket, and the pocket has an opening facing the front of the housing to permit an electrical connector of the image forming device to enter the pocket and mate with the circuit board when the replaceable unit is installed in the image forming device; and the replaceable unit further comprising: an inclined surface portion on outer surface of the first side in front of circuit board, wherein surface portion inclines outwardly and rearwardly from the front toward the outer surface, and a first guide wall and an opposing second guide wall outside the pocket on the surface of the first side of the housing between the inclined surface portion and the opening, the first guide wall positioned closer than the second guide wall to the top of the housing and the second guide wall positioned closer than the first guide wall to the bottom of the housing; and a cam ramp (185, 186) and corresponding support (187, 188) on the surface of the first side of the housing inside the pocket. an inclined surface portion on outer surface of the first side in front of circuit board, wherein surface portion inclines outwardly and rearwardly from the front toward the outer surface, and a first guide wall and an opposing second guide wall outside the pocket on the surface of the first side of the housing between the inclined surface portion and the opening, the first guide wall positioned closer than the second guide wall to the top of the housing and the second guide wall positioned closer than the first guide wall to the bottom of the housing; and a cam ramp (185, 186) and corresponding support (187, 188) on the surface of the first side of the housing inside the pocket.