... ISO 9001:2008 4.Acid resisitance(%):>99.6% Hardness-9.5 Grinding Ceramic Ball, Inert White Alumina BallsProfessional ... media Al2O3:17%-99.5%Size: 3,6,9,13,19,25,38,50MMVODA Inert Ceramic Ball ... 2.89>3.21>51 inch (25mm)>6.07>6.22>4.89>5.33>81-1/2 ... 92>5.33>5.28>82 inch (50mm)>9.7>9.8>6.22>8>15 Sample one:Sample ... with my mobile phone: 8618979999009. Hardness-9.5 Inert Ceramic Balls as Catayst Support Media