The new Shimano Ocea fluoro carbon leader has utilized the latest and greatest line manufacturing technology and strict quality controls from the world famous YGK line construction company to create the next generation in leader materials. Shimano Ocea EX Fluorocarbon consists of three separate layers that have each been carefully chosen for their individual attributes.1. The outer coating is Fluorine which creates a very smooth surface meaning that this line will travel through the rods guides effortlessly and with minimal friction.2. The next layer down is constructed from a harder fluoro shell material that gives the Ocea EX Fluorocarbon extra abrasion resistance and over all strength.3. The inner core has been engineered from a more supple fluorocarbon material that removes the stiffness of traditional fluorocarbon leaders and makes tying strong knots the clinch tightly easier and more reliable.