Material: Performance Glass Performance Glass (PG) fins are machine cut from layers of solid fiberglass. These fins are stiff, and are widely used by pro level surfers because the integrity of the flex is maintained under immense force, and in the most extreme of conditions and situations. The II Tool-Less Longboard System No need for a plate and screw. Ability to adjust your fin position in the box mid surf. Easily insert or remove your fin in seconds. No fin key required. Designed to be used in most existing Longboard boxes. No new box required.