1. Alumina content of ceramic valve: 95% 96% 99%. 2. Hardness(RoHS) 95% alumina ceramic valve: Alumina content of ceramic of moving plates: 1100 Alumina content of ceramic of stationary plates: 1050 3. Roughness of ceramic valve: 0.2 4. Aperture of ceramic valve: We can make the size as the requirement of customers 5. Paraller tolerance of ceramic valve: 0.01 6. Toleranceof ceramic valve: 0.01 7. Void ratio(Void ratio of shut): 20%