The Saltwater Barrier Gear System is an upgrade from the already proven Barrier Gear System. Built even tougher out of a new alloy that has been coated with Shimano's propriety Barrier Gear Coating, the gear not only lasts longer but stays smoother throughout the lifespan of the reel. The SW Barrier Gears are all cold forged with the grains of the metal lying adjacent to the gear teeth. This improves strength, durability and cranking power over other conventional gear systems.