This is an insulation accessory for Compact NSX 100/160/250 or EasyPact CVS 100/160/250. These interphase barriers reinforce insulation level at the power connection points. They are mandatory for voltages above 500 VAC for both fixed devices and adapters on plug in base. Interphase barriers are clipped easily between front or rear connection terminals. They are not compatible with terminal shields. They are not compatible with terminal shields.