O-z Gedney OZ-Gedney EF-75 Type EF Concrete Slab Electroform Straight Conduit Insert, Size: 3/4 IN, Malleable Iron, Finish: Zinc Plated, Dimensions: 2-3/16 IN Base Diameter X 2 IN Base Across Flats X 1-3/8 IN Height, Third Party Certification: UL File Number E-11853, CSA 009795, Applicable Third Party Standards: UL 514B, CSA: C22.2 No.18, Federal Specification W-F-408E, For Concrete Slabs 4 IN Thickness And Up, Threaded Rigid Conduit And IMC