From the Manufacturer

Bridgeport 282-DC 3/4-Inch Emt/Flex Coupling, Rigid/EMT Conduit Combination Coupling, Set Screw Emt To 1 Screw Clamp Flexible Metal Conduit Installation, Die Cast Ball Burnished Mirror Smooth Zinc, Trade Size 3/4 Inch, Size 1-5/8 Inch Dia X 2 Inch L, Approval Ul 514B, Standard Package 100, Used On Emt Conduit/Flexible Metal Conduit