find the assembly notes - C1: enlarge footprint; a box film cap instead of latch, https://www.neutrik.com/en/product/nc3fav-0 A Series, 3 pole female XLR receptacle, grounding: mating connector shell and front panel, steel retention lug, vertical PCB mount, additional ground contacts, https://www.neutrik.com/en/product/nc3mbv-e B Series, 5 pole female XLR receptacle, grounding: separate ground contact to mating connector shell to pin1 and front panel.