Abstract: A VXI product plug-in is provided herein that is capable of higher component density. The plug-in is configured to occupy two standard size slots of a standard VXI chassis, and includes two sets of three horizontally stacked modules in upper and lower sub-compartments of a front compartment of the plug-in carrier. The six modules have the capability of being populated with 480 switching relays, which provides for a 50 percent increase in the number of switches over the prior art plug-ins. The plug-in carrier includes a rear compartment that houses a VXI bus interfacing circuit, including a mezzanine board, a bridge board, and optionally a controller board, for interfacing the switch modules with a VXI backplane bus. The Plug-in further includes an internal backplane situated within the carrier between the front and rear compartments that provides an interface between the modules and the VXI bus interfacing circuit, and specifically, include a bus that can selectively couple modules together.