This Technora Survival Cord has a breaking strength of 450 lbs while having a diameter of just 0.08 inches. The secret of achieving these specs is in the material. This cord is made from woven Technora, a very high strength, low stretch, abrasion-resistant material. Additionally, it's coated with PTFE which provides both increased abrasion resistance and UV inhibition. This unique cord was originally developed for a US government agency to tether some sort of top secret airborne surveillance system. It is the strongest cord in the smallest package that will hold knots. This is a must-have for any survival kit.