Sponge rubber ball of Natural rubber with fine pores, quality firm type RM 270 (270±80kg/m³) orange. Sponge rubber balls are to be put in pipes and hoses to remove polutant. The balls should be choosen somewhat bigger than the tubediameter. By the elasticity, the balls produce a pressforce in their way to clean the tube. The cleansing takes place because of the special surface.