Flex 3/4 in. Screw-in Coupling (25-Pack) - The Home Depot
3/4 in. Flexible Metal Conduit (FMC) Screw-In Coupling The 3/4 in. Flex Screw-in Coupling is designed The 3/4 in. Flex Screw-in Coupling is designed to join 2 flexible metal conduits (FMC). The coupling is crafted with corrosion-resistant die-cast zinc alloy for strength and is suitable for indoor use only.