1.material:good quality natural rubber 2.density: medium and hard 3.size:10-170 4 withstand high temperature Standard sponge ballsDescriptionThe ... are soft, mid-soft, medium, mid-firm, and firm. For new equipment, soft and mid-soft balls are the best choice ... with sootStabilityNot available with acids, alkalis, oils, fats and solvents. High quality rubber sponge cleaning ball for pipeline cleaning