An electrical, electronic, fiber-optic, hydraulic, or pneumatic component is mounted upon a rectangular support body having an upper surface containing at least one linear groove, wherein a first connector is mounted in protectively concealed relation adjacent a given vertical side wall of the groove beneath an overhanging portion of the support body that extends partially into the groove, and a second connector extends downwardly from the component into the groove when the component is seated on the top surface of the support body. When the component is mechanically or manually horizontally displaced laterally of the groove from its initial inserted position toward a connected position adjacent the given vertical wall, the second connector is brought into connection with the first connector. In the preferred embodiment, the first and second connectors are electrical devices connected with electrical or electronic circuits contained within the component.