The 3221-40-0300-00 is a 1.27mm box header SMT (surface mount technology) type connector designed for compact PCB interconnections. It features a current rating of 1.0A AC/DC and voltage rating of 50V AC/DC, with contact resistance of 20 mO maximum and insulation resistance of 1,000 MO minimum. The connector is constructed with a Nylon 9T (UL94V-0) insulator body in black, brass terminals with gold plating, and operates reliably across a temperature range of -40°C to +105°C. With withstanding voltage of 500V AC/minute, this connector is ideal for industrial cable and connector applications requiring reliable, compact board-to-board or board-to-cable connections in space-constrained environments.