Canplas ElectraValve II E-box Plug With Leads, Replaces Nutone CI399EB#775851-EBX,

It is used to replace a defective connector included with a rough-in kit or to replace the romex plug that is connected to the old style ElectraValve that is replaced with the new style. #775851-EBX
Designed for use when connecting an older rough-in kit (CI395RK) to a new ElectraValve II wall inlet (CI399W or CI399ALM), this plug with leads is compatible exclusively with ElectraValve® electrified inlets. It is rated for 110 V and 2 A, ensuring reliable performance in your installation.

This replaces NuTon E-Box Only for use w/ CI399 Electra-Valve II Inlets