A Pirelli Mousse is a technologically advanced product, characterized by the presence of self-pressurizing agents capable of creating a very large number of gas bubbles inside the mousse, making the product immune to punctures, When new, they are equivalent to an inner tube inflated to 0.9 bar (equivalent to approximately 13 PSI); this pressure declines gradually along the life of the mousse, which must be replaced when it becomes too soft, Immune to punctures and abrasions; developed by Pirelli for riders who compete in every kind of competition, whether it be a race in the desert or a Cross championship trial, Technically the Mousse is a butyl ring with a honeycomb structure, the cells of which are filled with gas so as to simulate the effect of an inner tube, The Mousse is surrounded by a thin external membrane designed to make it easy to fit on different sized tires, Toroidal-shaped expanded-foam inserts replace the traditional inner tube on off-road motorcycles, 12-pack of 60-gram mounting lube tubes also available separately, Designed for use with Pirelli tires on off-road surfaces, Mounting gel lube included, Not recommended for road use