1. translucent 2. the end of resistance to high-temperature using temperature -200~+260 ? 3. corrosion resistance: resistant to acid, alkali, aqua regia, hydrofluoric acid and various organic solvents 4. insulation resistance: dielectric properties of temperature, frequency-independent 5. pollution prevention: metal blank value is low 6. extremely low solubility and precipitation, store standards, strong corrosion resistance, excellent expensive ultra pure reagent containers