Adapt Your 3.5mm stereo Jack For RS-232 Serial Control | Connector 1: DB9Pin Male ;Connector 2: DC3.5mm Male | Why Run All New Cables For RS-232 Control Of Your Audio/Video System, When You Can Use This Easy Adapter? | The Velocity RS-232 Adapter Leverages Your DB9 Or 3.5mm Stereo Audio Cable To Run 3-conductor RS-232 Control Signals Between Your Control Unit And Your Video Display.Fully Molded DB9 And 3.5mm Connectors Provide Excellent Strain Relief. | This Adapter Is Ideal For Use With Computers, Projectors, And Any Control Unit&Display Requiring 3-Conductor RS-232 Serial Control.