Don't know how to tie knots? No problem. Use the SwiftKnot Boat Docking Accessory at the end of your boat-docking rope. This makes it properly docking and securing your boat quick and easy. Made to use with double-braided nylon or 3-strand dock line. If docking stresses you out, here's how to eliminate pier pressure. 2-Pack. Makes it easy to properly secure your boat Eliminates the need to tie knots For use with double-braided nylon and 3-strand dock line 2 sizes for use with thinner and thicker lines