4ft Speedster Lightning Cord, Ultra Heavy Resistance - Bungee Bands for Speed Training 4ft Ultra Heavy Resistance bungee stretches 16ft. Last up to 10x's longer than uncovered bungees thanks to Safety Sleeve Technology Incredible Safety - Safety Sleeve Technology protects athletes from potential injury if bungee breaks during drills. Speedster Training Products are used by athletes, coaches, organizations and teams worldwide. Made in USA. 1 year conditional warranty.