The 1-1761681-3 is a vertical header assembly connector designed for printed circuit board applications. It features 40 contact positions with a standard 2.54 mm (0.100 inch) pitch spacing, providing reliable interconnection for electronic assemblies. The housing is constructed from polyetherimide (PCT) material with UL94V-0 flame rating in black color, while the posts are made of phosphor bronze with precision plating: 0.00038 mm minimum gold on the mating area, 0.00254 mm minimum tin on the solder end, and 0.00127 mm minimum nickel overall. The connector has a total length of 48.26 mm (1.900 inches) and mounting hole diameter of 1.02 mm (0.040 inches). This assembly is commonly used in industrial control systems, telecommunications equipment, and computer peripherals where robust vertical interconnection and high-density contact arrangements are required.