This product has the characteristics of antioxidation, erosion resistance and high strength, using togerther with nozzles, suitable for the needs of several heats and long time for the con-casting ofslab, round billet, rectangle billent, and spectal steel have the function of preventing the nozzles from block by blowing argon to the tundish nozzles. Al2O3 (%) > 60 A.P. (%) < 18 C + SiC (%) > 25 B.D. (g/cm3) > 2.65 ZrO2 (%) C.C.S (Mpa) > 20 Si O2 (%) M.O.R. at romm Temp. (Mpa) > 6.0 Refractoriness (篊) > 1770 Resistance to thermal shock (Times) > 5