Sigma Electric 49663 NM/SE 1-Inch Clamp Type Connector, 1-Pack Go to amazon.com Related posts Top recommendation for romex connector tool FeatureDie Cast ConstructionUse with 10-3 NM thru 4-3 NM CableThis product is UL ListedThis Product is CSA listed Description1" NM Connector from Sigma Electric. Sigma has been a trusted manufacturer of metal conduit fittings and weatherproof products for over 25 years.