This is a mini or "thinline" DC power jack. It has only 2 lugs, which means that it is typically used for pedals which do not have a battery snap. That is, it is for pedals which use a DC power adapter only. These are much smaller than the jacks which have an internal switch and an extra lug for a battery snap.
The power supply cord will fit quite tightly when you first use the jack, but will break in over time and continue to provide a nice secure fit.
The jack is insulated from the enclosure. For Pedals using standard BOSS-compatible power supplies, the short lug will be connected to Ground, and the longer lug to your positive voltage (typically ~9V+).
Fits great in a 5/16 inch or 8mm hole.
Designed to work with standard BOSS-style power supplies with 2.1mm diameter plugs. Available in an economical 10-pack.
|2.1mm Thinline Power Jack
Download Datasheet PDF