Porous rubber (the name “spongy, foamed, cellular rubber” is acceptable) is an elastic porous material obtained on the basis of mixtures with a high rubber content. The main component of porous rubber is often recycled rubber. This very budgetary and at the same time high-quality material, in turn, is obtained from automobile tires and rubber products. They are the source of that very high-quality rubber, which largely determines the basic functional properties of cellular rubber.