1,quartz substrate 2 tight tolearance 3,Resistance 1100 degree 4, no bubble no airline quartz substrate1,quartz glass disc2,tight siz tolearance3,Resistance 1100 degree, 2020 f4, no bubble no airlinePhysical PropertiesDensity 20oC g/cm3 2.2Softening point(oC) 1683Annealing point(oC) 1215Defoamation Point (oC) 1120Useful: Widely used in Medical, Electronics instrument, Scientific research, Optical ...