refers to specialized hardware, like guide rails or supports, that helps align and secure a Printed Circuit Board (PCB) when it's inserted into a larger device or chassis, ensuring reliable connection with connectors (often wire-to-board or board-to-board) for power/signal transfer, particularly common in rugged or industrial setups. These assists simplify assembly, provide strain relief, and guide the connector mating process, preventing damage during insertion or removal in frame-type plug-in units.