Produced in Japan with strict quality control, Shimano Mastiff FC is 100% fluorocarbon line offering anglers consistency and reliability with strength, durability, and smoothness to enhance performance on the water. But Mastiff's benefits aren't limited to increased smoothness and suppleness, the most significant characteristic of Mastiff cannot be seen with the eye. Shimano engineers devised NANOARMOR technology — nano-size ridges across the outer surface of the line — to enhance knot strength and toughness, preventing slippage and reducing the risk of line breakage. The added knot strength and durability are essential for enduring the repetitive stress when casting, twitching, or jerking large lures. Developed with one goal: Mastiff delivers connected confidence on the water.

• ICAST Best of Category Winner - Most Innovative Fishing Line: ICAST's New Product Showcase embodies the sportfishing industry's innovative and entrepreneurial spirit and rewards that ingenuity with awards in several categories. Mastiff clinched the prestigious award for its exceptional contribution to the Fishing Line Category.
• NANOARMOR™ Technology - Improves durability and increases the binding strength of knots: Featuring Shimano's innovative NANOARMOR™ technology, Mastiff significantly improves durability and increases the binding strength of knots. Imperceptible to human touch, these micro-ridges on the outer layer of the line prevent knot-slipping during battles with large fish and minimize slippage and breakage during common bass angling techniques like twitching, jerking, and casting large lures.
• Precision Manufacturing - Superior suppleness and surface smoothness: Mastiff is crafted in Japan using 100% fluorocarbon and subjected to stringent quality control measures. Rigorous inspection at the factory ensures an even surface down to just 1 micron, far surpassing the industry standards.
• Connected Confidence - Specifically designed to meet the demands of bass anglers worldwide: Mastiff's low linear elongation provides unmatched sensitivity, allowing anglers to feel the slightest disturbance on the line. Responsive performance and a supple surface enable frictionless casting, optimal control and effortless hooksets.