A replaceable unit for an electrophotographic image forming device, comprising: a housing having an internal reservoir for storing toner; and a circuit board retainer on an exterior surface of the housing, the retainer including: a top having an undersurface having first and second supports (304, 306) extending away from the undersurface of the top toward a bottom of the retainer and extending in a direction from a front of the retainer to a rear of the retainer, the front of the retainer facing a direction of insertion of the replaceable unit into the image forming device, the distal ends (320, 322) of the first and second supports (304, 306) positioned proximate the exterior surface of the housing; a pair of opposed side walls (342, 344) on the undersurface of the top, the opposed side walls (342, 344) positioned intermediate the first and second supports (304, 306) and extending away from the undersurface of the top toward the bottom of the retainer and extending in the direction from the front of the retainer to the rear of the retainer, each opposed side wall (342, 344) includes a bottom surface (352-1, 354-1) that faces toward the bottom of the retainer and is spaced apart from the bottom of the retainer; a circuit board seated against the bottom surfaces (352-1, 354-1) of the opposed side walls (342, 344), the circuit board including processing circuitry and electrical contacts (382 - 385), the electrical contacts (382 - 385) of the circuit board facing toward the bottom of the retainer; and the top and the first and second supports (304, 306) form an opening at the front of the retainer sized to receive an electrical connector of the image forming device for mating with the circuit board when the replaceable unit is installed in the image forming device. a housing having an internal reservoir for storing toner; and a circuit board retainer on an exterior surface of the housing, the retainer including: a top having an undersurface having first and second supports (304, 306) extending away from the undersurface of the top toward a bottom of the retainer and extending in a direction from a front of the retainer to a rear of the retainer, the front of the retainer facing a direction of insertion of the replaceable unit into the image forming device, the distal ends (320, 322) of the first and second supports (304, 306) positioned proximate the exterior surface of the housing; a pair of opposed side walls (342, 344) on the undersurface of the top, the opposed side walls (342, 344) positioned intermediate the first and second supports (304, 306) and extending away from the undersurface of the top toward the bottom of the retainer and extending in the direction from the front of the retainer to the rear of the retainer, each opposed side wall (342, 344) includes a bottom surface (352-1, 354-1) that faces toward the bottom of the retainer and is spaced apart from the bottom of the retainer; a circuit board seated against the bottom surfaces (352-1, 354-1) of the opposed side walls (342, 344), the circuit board including processing circuitry and electrical contacts (382 - 385), the electrical contacts (382 - 385) of the circuit board facing toward the bottom of the retainer; and the top and the first and second supports (304, 306) form an opening at the front of the retainer sized to receive an electrical connector of the image forming device for mating with the circuit board when the replaceable unit is installed in the image forming device. a top having an undersurface having first and second supports (304, 306) extending away from the undersurface of the top toward a bottom of the retainer and extending in a direction from a front of the retainer to a rear of the retainer, the front of the retainer facing a direction of insertion of the replaceable unit into the image forming device, the distal ends (320, 322) of the first and second supports (304, 306) positioned proximate the exterior surface of the housing; a pair of opposed side walls (342, 344) on the undersurface of the top, the opposed side walls (342, 344) positioned intermediate the first and second supports (304, 306) and extending away from the undersurface of the top toward the bottom of the retainer and extending in the direction from the front of the retainer to the rear of the retainer, each opposed side wall (342, 344) includes a bottom surface (352-1, 354-1) that faces toward the bottom of the retainer and is spaced apart from the bottom of the retainer; a circuit board seated against the bottom surfaces (352-1, 354-1) of the opposed side walls (342, 344), the circuit board including processing circuitry and electrical contacts (382 - 385), the electrical contacts (382 - 385) of the circuit board facing toward the bottom of the retainer; and the top and the first and second supports (304, 306) form an opening at the front of the retainer sized to receive an electrical connector of the image forming device for mating with the circuit board when the replaceable unit is installed in the image forming device.