This is the Speargun Band Tying Cinch Knot Cord 25 foot Constrictor Knot Cord Features:25 feet per package Speargun Band Tying Cinch knot cord has an aggressive braid that grips itself and never slips. It is the best material we have found for tying bands. With the thousands of bands that we tie regularly this knot has never slipped or failed us.