640501-3 is a 9-circuit PC board vertical pin header from the AMP Soft Shell Pin and Socket Connector series, designed for miniature rectangular connector applications. This header features a matrix style configuration with tin plating finish and is specifically designed for 0.120 inch (3.05 mm) board thickness. Key dimensions include an A dimension of 0.620 inches (15.75 mm) and a B dimension of 0.180 inches (4.57 mm). The connector housing material is UL94V-0 rated for flame retardancy and is RoHS compliant. It mates with socket housing part number 1-640521-0, making it suitable for wire-to-board interconnect applications in electronic assemblies.