The 2.80/2.50-4 foam filled tires are pneumatic tires filled with polyurethane. Its inside structure is microscopic, honeycomb-like cells which are formed by a matrix of tough urethane elastomer as below.

This kind of structure has the effect of shock absorption, making the products excellent in damping effect as good as air-filled tires, and free of maintenance ,making users feel comfortable while in use.
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