Sigma Electric ProConnex C-750 NM/SE Clamp Type Connector 3/4-Inch, 50-Pack Terminates NM or SE Cables to a 1/2-in knockout For 10/3 - 8/2 NM Cable, 0.52-in x 0.61-in by 0.51-in x 0.80-in Oval SE or 0.57-in - 0.69-in Round SE Tri-combo screws included Zinc die-cast construction Product is UL and CSA listed Sigma Electric