Owner Mutu Circle Hooks are made using a 2X strong shank. They are rated for use up to 50lb test line. This is the preferred hook for tuna fishing in Southern California on small grade fish, say up to 60 pounds.
This medium diameter hook doesn't damage the bait as much as a thicker hook, this allows the bait to swim more freely. Sometimes reducing the hook size will produce more bites and this hook is still very strong even in the smaller sizes.
Just remember to not swing the rod when you get bit, simply turn the handle on the reel until it comes tight and the line starts ripping off the reel.