Protective plastic covers for treble hooks, they have a patented “easy grip” feature for quick on and off, and a hollow design that allows hook points to dry, thus discouraging corrosion. Treble Sizing: X-Small – 12, 10, 8. Small – 8, 6, 4. Medium – 4, 2, 1. Large – 1, 1/0, 2/0. X-Large – 1, 1/0, 2/0, 3/0. XX-Large – 2/0, 3/0, 4/0, 5/0.