Description Made of durable, lightweight urethane, Mr. Tuffy provides a protective layer between the outer tire and inner tube. Urethane has a property which makes it very elastic. When a thorn or piece of glass attempts to penetrate the Mr. Tuffy liner it comes up against a surface that is both hard and elastic. The object pushes against the surface which gives way while resisting initial penetration. Guaranteed to prevent flats and made in the USA! Lightweight-Weighs less than liquid fills and thorn-resistant tubes Easy installation-no gooey mess Absolutely, positively, will not cause tire or tube to damage or loosen spokes Eco-friendly and reusable from bike to bike and biodegradable when disposed
