Package: PJ9; Plug/Jack: 3.5mm Jack; Stereo/Monaural: Stereo; Number of Poles: 3 Poles; Form: Straight; Terminal Treatment: -; Material: Plastic; Note: Panel Mounted; Stereo mini jack with panel mount. Cylindrical shape saves space and all terminals are connected at the back of the wire for a clean maneuverability. The back is covered to prevent dust and foreign objects from entering. The sleeve (ground) terminals are non-insulated in conjunction with mounting screws, so they can be connected to the panel by attaching it to the same type of conventional models. About insulation and non-insulation; Panel mounted RCA pin jack, φ3.5 jack, etc. can be divided into both "insulated type" and "non-insulated type". Insulated or non-insulated means when the connector is attached to a panel it says "whether the GND terminal of the connector comes into contact with the panel". Insulation type items do not connect the GND terminal of the connector to the panel (contact). The non-insulated type is electrically connected when the panel is made of metal. The insulated connector is used when you do not want to make "GND" loops. What is GND loop; The wire is a loop (loop), especially the GND wire loop is called "GND loop". When the magnetic flux is stranded with the loop, the current will flow into the GND line, which creates a voltage that is a noise. If this happens, you can cut the loop to prevent the noise caused by the interlocking magnetic flux.