C2G/Cables to Go 02444 Velocity DB9 Male to 3.5mm Male Serial RS232 Adapter Cable (1.5 Feet, 0.48 Meters) Adapt your 3.5mm stereo jack for RS-232 serial control Connector 1: DB9 Male Connector 2: 3.5mm Male Adapt your 3.5mm stereo jack for RS-232 serial control onnector 1: DB9 Male Connector 2: 3.5mm Male Pinout: DB9 Pin 3 to 3.5mm Tip; DB9 Pin 2 to 3.5mm Ring; DB9 Pin 5 to 3.5mm Sleeve