Spearit's Heavy Duty Kevlar®² Constrictor

We recommend our heavy duty constrictor for band sizes 5/8 inch and thicker. At 400lbs tensile test strength, it gets the job done with a single constrictor knot, even on 3/4 inch rubber

Why Kevlar®?

Like most spearos, we used waxed Nylon lacing cord as constrictor for years. Why was it waxed anyway? To lubricate it so that it could be tightened without breaking. Besides being weak the other problem was the stretch. Terminal beads and knots had to be larger to compensate for the stretchy constrictor. But the larger the bead, the more stress on the rubber which is why most band breaks occur over the bead. We wanted to use the smallest beads and knots possible so we knew we needed a better constrictor. Kevlar® fit the bill. its super strong so a constrictor knot or two will do the job. It is ultra low stretch so that when you tighten down your constrictor knot, it stays tight. Last but not least it is much better at retaining a knot than any other synthetic fiber. Say good bye to keeping a lighter around to melt a ball on the ends of your constrictor to control knot creep. With our Kevlar®² Constrictor you can cut it close and forget it or if an 1/8 inch tail offends your sense of perfection, tie an extra constrictor knot on top of the first and cut it off flush.