May 10, 2013 Always seem to loose this information Common Hole Sizes: led: 3/16″ little black LED holder: 1/4″ toggle switches: 1/4″ potentiometer: 5/16″ input/output jacks: 3/8″ DC jack: 1/2″ 3pdt stompswitch: 1/2″ Download WordPress Themes Free