Jinkai Sleeves are made from a special aluminum alloy that is easy to crimp and resists electro-corrosion in saltwater. The soft metal and oval shape work together to provide a permanent crimp without compromising line strength. A wide variety of sizes coordinate for use with all lb. tests of Monofiliment, Copolymer and Fluorocarbon fishing lines, available in packages of 50 and 500. use Jinkai tools for the best performance.