The Airhead Bungee Tube Tow Rope - 15m has a 0.95cm diameter bungee cord spliced inside. It's rated at 1.88kg tensile strength, conforming to WSIA recommendations for 1 - 4 rider tubes. You'll enjoy brief surges of speed as the bungee stretches and contracts. It reduces wear and tear on tubes and riders too, by absorbing sudden jerks from slack in the line. A Rope Keeper is included for convenient storage.