The 640841-1 is a Packard-style receptacle terminal from the FASTIN-FASTON product line, used for creating reliable electrical connections. It is constructed from brass and is designed to accept a wire range of 20-16 AWG with a maximum insulation diameter of 0.145 inches (3.68 mm). These terminals are often used in multi-position connectors and feature a locking lance for secure retention in housings. Common applications include wiring harnesses where they serve as coupling connectors, providing time savings in final assembly.