Penetration Hooks newest 4/0 Model is the F Hook, The F hook was designed for fishing in open water. The F Hook was made with the same wire thickness as the E hook and fits the same length of baits (6- 10) Inch baits that are a little thicker in diameter. The 4/0 gap is better to use with the thicker baits because it allows more room for the bait to be pushed down and the Barb to be exposed and set into the fish's mouth. The F Hook uses the super sharp Penetration Hooks Barb that has no problem piercing through even the toughest skin on the fish's mouth! The F hook is great for Flukes, ole monster worm, power worms, 6 Senkos and Magnum Trick worms.