Mousse Tube - 21" Intended to prevent tire deflation in case of puncture caused by perforation, shock or pinching, Mousse insert replaces the inner tube and is designed exclusively for off-road competition, Fitting pressure and stiffness are equivalent to an air pressure of 13 psi, First and only mousse to a 2 year shelf life, Special mousse grease included in box, Made up of a honeycomb structure