A clamping mechanism is provided for attaching an auxiliary apparatus to a weapon having a frame. The clamping mechanism has projections which are biased by a flexible member toward corresponding recessed portions formed in the frame of the weapon. A retaining member is also provided which may be moved between an open and a closed position. In the closed position, the flexibility of the flexible member is minimized, such that the projections of the clamping mechanism are locked against the corresponding recessed portions of the weapon. In the open position, the flexible member may bend away from the weapon thereby disengaging the projections of the clamping mechanism from the recessed portions of the weapon. A battery housing is also provided for receiving a battery casing which holds one or more batteries. The batteries are provided for energizing the auxiliary apparatus. The battery housing has a cavity formed therein. A recessed portion is provided in the surface of the cavity for receiving a projection formed in the battery casing. A spring member is provided for biasing the projection of the battery casing toward the recessed portion of the cavity to maintain the battery housing in a closed position.