Upper Conn.: Banana Jack Material: Brass rod per ASTM B16-85, Temper H02. Finish: Nickel plated per QQ-N-290, Class 2, 200/300 micro-inches. Insulation: ABS molded to banana jack and pin tip body. Marking: “1432 POMONA ELECTRONICS CALIF.” Lower Conn.: Pin Tip Plug Material: Brass rod per ASTM B16-85, Temper H02. Finish: Nickel plated per QQ-N-290, Class 2, 200/300 micro-inches.