A network device including a mounting rail having at least one mounting location. The mounting location defined by one or more device reference locators that define a mounting direction relative to that mounting location. A device connector attached to a device printed circuit board (PCB) is positioned to have a connecting direction parallel to the mounting direction.At least one module is provided for mounting to one of the mounting locations. The module including one or more module reference locators each adapted to engage one of the device reference locators when the module is positioned to be mounted to the mounting location. A module connector attached to a module PCB is positioned to have a connecting direction parallel to the mounting direction;The module connector and the device connector are positioned such that when the one or more module reference locators are each engaged with the one of the one or more device reference locators, and the module is advanced in the mounting direction towards the mounting location, the module connector and the device connector connect as the module mounts the mounting location to connect the module to the network device.