Here is a handy design for a knot reference! Waterproof plastic cards mean you can take this little reference (just 2 1/4 x 3 1/2) with you on your boat and not worry about it getting wet or damaged! Six cards are attached together in corner with a brass grommet. 20 useful knots cover most any rope tying situation: Bowline, Square Knot, Water Knot, Rolling Hitch, Sheet Bend (Double Sheetbend too), Trucker's Hitch, Buntline Hitch, Mooring Hitch, Tautline Hitch, Cleat Hitch, Clove Hitch, Constrictor Knot, Double Fisherman's, Figure Eight Follow Through, Prusik Knot, Sheep Shank, Timber Hitch, Butterfly Knot, Two Half Hitches, and the Bowline on a Bight. A set of these PRO-KNOT cards belong on your boat and in the glove box of everyone's car or truck!