The vertical jack allows the printed circuit boards to be mounted parallel to the front panel, which helps keep module depth to a minimum.
The threaded diameter measures around 5.9mm (0.232"). Drill holes 6.1mm (0.240") from Front Panel Express have been tested to have a nice fit. The punch used for Erthenvar production panels is 0.244" in diameter.
Comes with hex nuts; washers not included.
These are the same audio jacks are used in Synthrotek modules.