Insulated Set Screw Connector 3/4″, Die Cast Zinc
https://nsiindustries.com/product/insulated-set-screw-connector-3-4-die-cast-zinc/
Use Bridgeport insulated set screw connectors to join flexible metal conduit (FMC) to an electrical box or enclosure. Insulated throat protects inner wiring from abrasion and is rated up to a temperature of 105°C.