Paracord pans are, of course, already familiar with the Fish Bones and Piranha's. This Diesel Fish is a that great tool enables you to secure your paracord without tying knots. The basic principle of all versions is the same: you place the end of your paracord on your Diesel Fish and wrap it around it. Because of friction your paracord will be properly secured. The other side is wrapped around the head of the fish twice. The fact that it also functions as a bottle opener is a nice bonus!