Mono TS enclosed 1/4" jack. Solder terminals for ground and tip.
Gripping teeth on jack casing that grabs onto the inside of the enclosure. Cuts through any paint or powder for a solid ground connection in every scenario. Also prevents the jack from rotating while tightening or loosening over time.
Solder lug holes are small, you'll probably have to wrap a wire around the lug if you're trying to wedge more than one in there.