Bridgeport 257-I 3 IN Steel Ins Comp Conn, Box of 2
https://nsiindustries.com/product/insulated-emt-compression-connector-3-zinc-plated-steel/
Use Bridgeport screw-on EMT compression connectors to join electrical metallic tubing to an electrical box or enclosure for a concrete-tight seal. An insulated throat protects inner wiring from abrasion and is rated up to 105u00b0C.