AT Series Circular Connectors Amphenol Industrial AT Series Circular Connectors feature Amphenol's AT contact technology and are designed for truck environments and demanding applications found in construction and farm equipment. The molded thermoplastic connectors offer a positive bayonet retention system and are sealed by redundant grommet wire sealing. The square flange design ensures a drop-in replacement to existing panel design while the jam nut design makes for easy installation. The 9-pin black receptacles are in accordance with the interface of the diagnostic connector of J1939/13. Amphenol Industrial AT Series Circular Connectors are RoHS compliant.