The PD-0103-01 is the stereo Switched Output Jack (4 contacts) used in the Acousti-Phonic Preamp kits. Replaces your 1/4" output jack and provides automatic Stereo/Mono mode switching and power on/off functions.
The PD-0103-01 is the same stereo switched output jack that is used with the following Graph Tech ghost preamp kits:
Ghost Installation Manual
Ghost Acousti-Phonic Frequently Asked Questions