1-178138-3 is a board-mounting header connector from the TE Connectivity Dynamic D-3200S single-row high voltage series. This horizontal type header features a 5.08mm pin pitch with tin plating and black color housing. The connector has 3 positions with X key configuration and dimension A of 29.2mm, B of 22.1mm, and C of 10.9mm. It is designed for wire-to-board applications in industrial environments and is RoHS compliant, making it suitable for applications requiring reliable high-voltage connections.