Medium temperature magnesium oxide powder with silicon 1,temp 650-700C 2,heavy silicon treatment 3,water heating element Medium temperature magnesium oxide powder with silicon1,temp 650-700C2,heavy silicon treatment3,water heating elementHTM 900-1100C HIGH TEMPERATURE POWDERMTMS 650-700C MIDDLE TEMPERATURE POWDER WITH SILICONMTM 700-750C MIDDLE TEMPERATURE POWDER WITHOUT SILICONMLTMS 550-600C ...