J-plugs are very deadly baits. Especailly when fall running kings start to mature and and hit out of aggressiveness. Only problem with running them on riggers is they have a tendency to go back and forth quite a bit and can tangle other lines easly. We use the #4's most of the time for kings but #5's can be deadly when they have quit feeding, they will attack these with force. Also the ones with a the rattle inside seems to make a big difference also.