Features: High purity completely eliminates contamination.Chemical resistance, high stability against a variety of solvents.Heat resistance, high dimensional stability over a wide temperature range.Transparency, high transmissivity over a wide range of wavelengths from the UV to IR.Fluorescence, no fluorescence over a wide range of wavelengths from UV to IR.Dielectric properties, low dielectric loss even at GHz frequencies.Surfaces have high flatness, high uniformity of thickness (parallelism) and smooth surface < 0.3nm roughness.